Check out Action Photo School for ton's of sick tips/techniques for shooting skiing!
There may not be another site in the world with as much great action content in one place as APS, but if you do a bit of searching, there are some good articles to be found. Here's a few of our favorites.
How To Shoot Snowboard Photos – A bunch of great, simple, and important tips on shooting snowboarding.
Skateboarding Photos – Tons of great, and important, tips for shooting skateboarding action.
Surf Photography for Beginners – Equipment, Techniques, and Tips – From Digital Photography School, this article will explain all the basics for anyone looking to start shooting surfing. Be sure to look around the rest of the site as well since it's FULL of great articles.
Capturing the Action in Sports by Peter Skinner – Some very useful tips for anyone just starting to shoot action, or for those of use who may have forgotten some of the basics.
How to Shoot Mountain Biking Pictures – Part 1 – Awesome article explaining all that you need to get started shooting mountain biking. Chock full of great images! Finished reading part 1? Check out Part 2, and Part 3