With so many 3d programs ,Houdini, 3dsMax, Zbrush, Maya, Rhino,Realflow,Vue 7,Cinnema 4d and not to talk about the Adobe CS3 and 4.
These programs in dollars amounts to at least $20 000.00 thats before you even got started.
Some of these companies do have "Apprentice" and PLE (personal learning editions) non- commercial versions to help struggling students to get to wraps with the somewhat complex UI (user interface).
But they do have limitations to them .
Some have 30 day trails to get you enticed to buy the product .
There are various ways to go about, getting your program for free.(Not Recommended)
Torrent sites and p2p sites is helpful, for those who feel the that $500 -$10 000 for a program is a bit steep
But there is allot of virus, worms etc... that could harm your computer!
Once past all this red tape you need to start learn the program itself and this could be time consuming and frustrating,plus you have to have a lust for pushing the frontier working in virtual space to make the impossible, possible!
Then you know you are on the right track .
There are tons of tutorials online to help the starting digital artist to get to grips with the programs,also helpful places is forums where pros can be helpful with tips and tricks.
Once you trough deep waters you can start to work independently trough sites like Odesk.com
Where you can submit your portfolio and do some competence test to prove that you know the software you claim to be able to operate .
Then you bid or apply price wise for dozens of jobs which you might just end up getting .
Digital art is here and the medium is definitely pushing the frontier into place where no man has gone before!