A great little free (although they certainly do accept donations) animating program you can download from the web is called Pencil-appropriate enough because it leads you back to the days of animating basics. This little program is the electronic age version of the old animator light table where one would sit and draw pencil rough character and bring them to life via traditional animating techniques. If you have the craving to jump into the wonderfully time consuming world of animation and don't want to be sidetracked with a lot of shortcut tweening functions offered in costly 2d animating programs then my suggestion is to pick up Pencil. The drawing and animating tools are about as simple to learn as you can get but not in performance. This little prog can do wonders in keeping up with the bigger platform software packages. Made to function at its best with a graphics tablet Pencil still allows you to draw with a mouse (keep that hand steady) however tablets only allow the pressure sensitivity pen width function so be prepared. Pencil supports an audio track so you can put music or sound effects in your production however, one area it falls short is the ability to see a wave form on the timeline to help synch up your sound-ends up being a lot of trial and error with the audio.
I would have to say that Pencil is a great program to hone your animating skills but as far as full production goes, you could end up wasting a lot of time get it to perform as well as other programs like Toon Boom or Flash...but then again, Toon Boom isn't free, is it? Pencil is available for both PC and MAC platforms with an online manual and support forum so if you feel up to polishing those keyframing skills, go download Pencil today.
