You probably want to go with 24fps, but you might be happy with the look you get from 12fps.
If you're doing movement, you should only shoot 1 frame before you move your model. A simple hand wave would go something like this:
- Shoot one frame on the far left
- Move the hand slightly to the right
- Shoot a frame
- Move the hand further to the right
- Shoot a frame
- Repeat until the hand if far right
- Reverse the process, shooting a frame, then moving the hand a little to the left...
When I first tried stop-motion, one thing I found useful was to film myself performing the action I wanted to replicate. I then watched this back, frame by frame, and tried to copy what I saw in each frame.
There's tons of tutorials on Google. You should start looking there...