Start with the tutorial sections here. You'll also find a wealth of material at www.poserpros.com (Well over half of the site is nothing but tutorials and discussions about technique). I run the P4 forum at poserpros, and I'll be posting a massive FAQ for basic users in the next week. It'll be explaining everything from how to get an article of clothing on a model to what happens when the lights suddenly turn off. Also, do a search through here for tutes by Dr. Geep. The man knows Poser inside and out.

docandraider.com -- the collected cartoons of Doc and Raider