As mentioned, you can use Blender, which is free and Maya, which will cost you a lot of money. I have tried to teach myself Blender some time ago, but then I went back to 3D Studio Max in that, you know, OTHER OS
, because I was doing a course in 3D animation (my 2nd), and that's what they were teaching. I would prefer Max because it is far more developed than Blender (I would *hate* to get a great idea for an animation in my head, but then find I'm not able to make it on the computer because the software is lacking), but anyway, it's advancing steadily I think and there's PLENTY to be done with it. The Blender site has links I think to lots and lots of tutorials, including video tutorials, so .... have fun!