Take as many skiing lessons as you can with the highest level instructors possible, or if you're young enough join a team. Best way to learn fast and get good. Prevents bad habits and makes things MUCH easier.
Don't go straight to the park. Ski the mountain a bunch too.
Talk to some skiers you know about skis, if you like the anthems then pick up a pair if possible. Freeskier.com also has a very useful gear guide on it.
Those poles? They do have a purpose. Grab some and learn to use them, if ONLY for skiing outside the park.
Ski boots.... See a boot fitter. Don't make the mistake of buying boots that are big so you can grow into them. It will ruin your entire season. Full tilts are a good option for quality boots that won't set you back $800, plus they have a really good liner that won't pack out a ton like others. But don't buy full tilts just because you hear they're good - boots are all about fit, and full tilts have quite a specific fit.
When you start using your boots, it WILL hurt. Wear them skiing, at home, wherever and whenever possible to break them in as fast as possible.
Those mogul bumpy thingies? They're much more fun on skis.
Mount your skis at the recommended line. There is only really one mounting point on skis.
Skiing style and tricks are completely different than snowboarding - we see things in a very different way. Check out the video section on the site to familiarize yourself a little more with skiing. Don't stop looking at stuff from a snowboarding perspective though - keep that as the way you view things as a snowboarder can make for some very unique style.
Don't fuck with your DIN settings. Get your equipment adjusted by someone who knows what they're doing.
BUT most importantly.... HAVE FUN.
