but there is also Blender, which is a free, open source, 3D modeling and animation program. It actually is pretty powerful...but a pain in the ass to learn.
C4D really is a good software if you're very new to 3D animation, since it's really user friendly, easy to navigate in and its system already has features of which you can simply drag and drop and get the effect you want.
However if you're looking at the long run, I'd suggest trying out Maya or 3ds Max, since most companies that produce animation for almost every game/movie uses those. The downside is that they're pretty hard to learn though!
I've personally used 3ds max for about 10 years now. I'm obviously a little bias. If you want to get into the top tier of things I'd suggest Maya. Thats what all the bigger teams are switching to. C4D, Blender, XSI are all okay... but its not as uhhhh "mainstream". I find theres a lot more help for things like maya / max. Be warned though Maya is very unforgiving and not very user friendly to start out with. Doesn't hurt to learn though. As for post FX I've always used After Effects, although theres alternatives like Sony Vegas or even something like Nuke. Just do some research.