At the risk of being bodily ejected from the forum; start with some basics.(and free stuff)

Daz Studio - the minor contender to Poser. You can get the basic idea of how Poser works, and when you're ready, upgrade to the real deal...Poser...;)

Bryce 5.5 - is on the web, and free. Note - Bryce and Daz Studio talk to each other, so you can do landscapes with it, and put people in them.

Wings 3d, blender, anim8tor - modeling programs, if you go that way. There's a '3d point', where every Poser user comes here and asks 'how do I make my own clothes?"...;) Believe me, there's enough freebies here and other sites to fill up your Hard drive with gigabytes of stuff (believe me, I've done it...;)

Some of the Poser textures are done in Photoshop, I don't have Photoshop, but some of the skin and clothes textures are available that way (psd files?)

I wish I'd said that.. The Staircase Wit

anahl nathrak uth vas betude doth yel dyenvey..;)