I would recommend using adobe flash as the animation software. (i think you can get the trial version for free) or if your college or uni provides one, that's even better. (mine does)
Watch this YT video and practice.
I think the best way for you to learn as much as possible is to experiment with variety of different tools to know exactly what each one does... but I'm not stopping you from using other resources.
Here are some links for free software.
If I were an animator I would rather purchase flash than use any of those. I don't know, maybe because I've been using it for quite a while and it's really convenient for me.