I used After Effects and Shake to composite Panzer Corps, if I had to learn only one I would pick After Effects. First off After Effects is an industry standard program, meaning small companies to effects giants all use after effects in some way. Secondly, it is the best program for motion graphics.
There is no reason to reinvent the wheel, Andrew Kramer (After Effects God) has already made a fantastic series of basic After Effects tutorials. His advanced tutorials are even more amazing! (click the image below to visit his site!)
