You would think buying skis would be fairly straightforward, but it can get a little complicated, so we're here to help find the right set for you. The basics are all here. Remember that it's not only the ski that's important, but also the binding — for instance, you can turn a downhill ski into a cross-country one simply by changing the binding. So let's get stared.

Kinds of Skis

Alpine/Downhill
Alpine or downhill skis are for the mountains, and for those skiers who like groomed runs (in other words, you're not a powder junky, always looking to ski in fresh, ungroomed snow). If you're looking to get a pair of skis and hit the downhill slopes, these are your baby. There are three different kinds of Alpine skis
All Mountain
All mountain skis are a kind of Alpine/Downhill ski. They can handle powder or piste (the groomed surface of most ski resorts), but more are usually a little better on piste. These are also good if you like both powder and piste, and don't want to have two pairs of skis to enjoy them.
Freeride
Freeride skis are also a kind of Alpine/Downhill ski. Freeriders can handle pretty much anything that's thrown at them — powder or piste, but lean a but more towards the powder. Freeride skis tend to have a cut and design that is best suited for advanced and expert skiers, so be warned.
Carving
Carving skis are also a kind of Alpine/Downhill ski. They are short skis designed for people who want to carve up the slopes — cut back and forth, a lot.
Cross-Country
Cross-Country skis come in many shapes and sizes, so first let's be clear about what you can expect. "Off-track touring skis are for powder, while "In-track" skis are mainly for groomed spaces where there won't be as much fresh powder.
Backcountry
Backcountry skis allow you to not only slide through the countryside, but also to climb up hills and ski down other ones. They usually have metal edges and are nearly as wide as most Alpine skis. Backcountry skis tend to be wider and sturdier then Nordic skis (see below) for the simple reason that they are designed to carry you and your gear. If you currently have Alpine skis, you can try Alpine Touring attachments on your current skis to see if backcountry is for you (the AT attachments allow you to lift your heel when climbing). But serious backcountry aficionados should probably invest in skis designed for all the pleasures that only backcountry skiing can bring.
Nordic
Nordic skis are more for even cross-country skiing across groomed runs. These are the traditional in-track touring skis that are most suitable for paths that have already been broken in. Because they're not designed to hold the weight of extra gear or to go down steep hills, these skis are generally lighter than AT or Backcountry skis.
Skating
Skating skis use an inline skating style on groomed trails. Skating skis are narrower, shorter, and lighter than other traditional cross country skis.
Alpine Touring (AT)
skis are the do-everything ski, from going across the countryside to climbing hills to cruising down the backsides. AT skis usually are light (too heavy and it will be too much work) and have a fair amount of flex. Remember, you can start off by getting AT attachments for your current skis to see if a true pair of Alpine Touring skis are for you.
Telemark
Telemark skis, much like Backcountry or AT skis, can be used to glide across the countryside, climb hills or shooting down them. Telemarks have a unique design that reflects some important differences. Alpine skis are designed to have most of the weight on one ski when turning (the bottom ski), which means they need to be able to withstand that pressure. Telemarks are designed for skiers to split their weight 50/50 in a downhill turn, with the back leg doing as much work as the front. That's another way of saying they're not for beginners.
Twin tips, jumping, ski boards
Twin tip skis are designed for snow parks where you will spend most of your time in a half-pipe or other obstacle course.

Kinds of Skiers

Someone once said that 80% of all skiers are intermediate, but that 80% of them think they're experts. The bottom line is that buying a ski above your skill level will be a waste of your money and your time, so choose carefully. Here's a rough guide:

Beginner/Intermediate
If you've only been skiing for weeks or a few years, you're probably here. Green and blue runs don't bother you, but black and above make your heart race and your legs ache. Moguls and ice is definitely not for you. You probably can't tell the difference between a tuned ski and a non-tuned one. The vast majority of us fall into one of these categories. It's okay — embrace it and buy the right ski. You'll have a far better time. Trust us.
Advanced
Advanced skiers can ski the entire mountain — front, back, piste, powder. Off-piste and bumps might still rattle you now and again, but you're pretty solid everywhere you choose to ski. You can tell when your skis need to be tuned.
Expert
You seek and thrive on challenging runs, and can ski in any condition extremely well. You like skis that are stable at very high speeds, and can handle the terrain no matter how dicey it gets.
Race
You know who you are: either a paid, sponsored professional, or pretty darn close to being one.

The Shap of Your Skis

Sidecut
All modern skis have a sidecut so that they can turn. Without it, your skis would want to go straight when you decided to cut left or right. "Carving" skis have a pronounced sidecut so that they can cut back and forth on the slopes without dumping their owner on his or her neck. By contrast, Nordic skis, which see few turns, have very little sidecut and are relatively narrow.
Technically speaking, sidecut refers to the long, inward curves on both sides of a ski. It's designated by 3 numbers: the widths, in millimeters, of the ski's tip, waist and tail. The greater difference in these numbers means the larger the sidecut.
Width
Ski width is typically measured in three areas: the width at the tip, at the waist, and at the tail (for example, 122/90/115). These measurements give you an accurate idea of the uses for a ski. Generally, whether an alpine or a cross-country model, your ski needs to be wider if you're going to be skiing on powder. This spreads your weight out and lets you glide over the snow, instead of plowing through it. Wider skis also provide a more stable platform, which makes them easier to balance on when moving through variable snow conditions.
You don't need to worry about width too much unless you're a powder junky.
Length
Very basically: Shorter = easier. Longer = harder, but faster. Because of the sidecut, skis no longer need to be long to give you plenty of stability at high speeds. As a general rule, most beginner and intermediate Alpine skis should come between your nose and forehead. But you need to consider the type of skiing you'll be doing, your skill level, and your weight. All these things impact how long a ski should be.
Generally, beginners and intermediates should stick with shorter skis for ease of turning and better control. Once you move up to greater speed and different kinds of conditions, you can begin to play around with your ski length — and longer might in time be better for you. A very rough guide for beginning alpine (downhill skis) skiers is:
Weight (lbs) Ski Length (cm)
Less than 100 140
101-115 145
116-130 150
131-150 155
151-175 160
176-200 165
200+ 170+
DIN Setting
The DIN release setting is just simply how easily your boot pops from your ski. To save beginner's knees, the DIN setting is usually set generously low. More advanced skiers need to have the DIN set higher so that their aggressive moves don't pop the boot from its binding — a major drag. The DIN is set according to skill, weight, and type of ski.
Flex
There isn't really a "flex" system, but just a few pointers here. Your skis' flex, or stiffness, is directly related to its performance. Beginners generally want skis that bend more easily, because they are a little easier to control. Stiffer skis are better for performance in crud, boilerplate, and varied snow conditions. But stiffer skis require more energy and skill to turn and move, so there's always a trade-off.

Alpine Bindings and Mounting

Bindings, like skis, come in many forms, shapes, and sizes. Remember that you can convert an Alpine ski to a cross-country one by changing the bindings to Alpine Touring (which simply lets your heel come up).

Generally, it's important to simply have the right kind of binding for the right kind of ski and the right kind of skiing. Obvious, right? Just in case, here are a few basics:

  • Forward Pressure — advanced forward pressure mechanisms can help to keep your skis retained under a lot of flex and pressure.
  • Release Direction — make sure you toe and heel pieces release in a way that makes sense for your skiing style. So, to be obvious, Alpine ski bindings should release vertically and Nordic ski bindings horizontally — the most likely way you'll apply the wrong kind of pressure to these skis.
  • Antifriction Device — antifriction devices (AFD) ensure you ski will release in any condition.
  • Lift — this simply provides some clearance for your boots in turns. Carver's, for instance, often have bindings that lift the boots in turns.
  • Vibration Dampening — no point in rattling your teeth loose if you can help it. Dampening devices absorb the bumps and grinds of the mountain, so you don't have to.

Cross-Country Bindings

There are two general cross-country bindings available. There are subcategories within these, of course, but all conform in most ways to one of these basic designs.

The NNN (New Nordic Norm) has a bar in the toe of the boot that hooks to the binding. A more aggressive form of this is known at the BC (Back Country).

75 mm (Rottefella, Nordic Norm, 3-pin) are the time-tested bindings originally used on all cross-country skis. Time-tested, which means they're reliable, durable, and work well.

Telemark Bindings

There are 4 general kinds of Telemark bindings, which will briefly go over here.

Neutral Cable
Newtral cable is where it all began. Neutral cables are strong, dependable, and time-tested. Cables exit the toe piece that allows the heel to rise up, and your body motion and gravity lower your heel back down.
Active Cable
Active cable does a little more of the work for you. Unlike neutral cables, an active one will pull your heel back down toward the ski after each motion, which can make moving a little easier.
Free-Pivoting Touring
Free-Pivoting touring moves the point of contact forward so that the binding pivots at the front of the toe, instead of the ball of the foot. These makes these bindings more like AT ones, and thus great for backcountry.
Releasable
Releasable bindings are just what they sound like, and for serious Telemarkers who may be concerned about avalanche and the need for serious speed.

AT Bindings

Most AT skis come with traditional step-in bindings. These are heaver than the newer Dynafit bindings, but they allow for aggressive downhill skiing.

Speaking of Dynafit bindings — they're super light-weight, which makes climbing up hills a lot easier. Of course, they're not as good if you're looking to ski aggressively on the way back down, but many think the trade off in weight and easier movement are well worth it.