Rhino is an excellent way to get into 3D. So are the other two programs. However, their interfaces can be a little daunting at first. If you can afford them though, you'll be better off in the long run as there are more job openings for people who have mastered 3DSMAX or MAYA. However, if money is an issue, Rhino is a great program with lots of power, excellent support and easily accessible. Not to mention Renderosity has THE best Rhino forum on the internet...and no, I'm not just saying that because I help run it. :)