I know it doesn't answer the question, but basically After Effects is a MOTION GRAPHICS program... the working interface is like Photoshop and Flash, but you pump out ... MOV files, image sequences, PSD sequences etc.
so you'd have to install AE and maybe watch a video on the GUI... if you are familiar with Adobe you're going to feel at home in AE.
what I think you want to do is this:
export your PSD files as individual layers
create a comp in AE to the size and time you want (everything in AE is Rastered so have all your stuff at the largest size possible before putting it into AE)
then ... you drop your layers into the movie comp, just like you would in Photoshop...
once the layers are there... you can set keyframes for their positions and animate them as you wish.
if you are going to be doing motion graphics (making photoshop or illustrator stuff MOVE) then you want (i would say need) to use AE.
AE is made to add effects to video, its literally a Special Effects application but it will treat still images just like movie files.
you'll also find that a lot of effects in AE just ... look better than they will trying them in PS... the main example is anything with light... light in AE looks... real.
I can't give you a full tutorial on AEE here but, again... if you are competent with how Adobe's programs look and work, then you'll settle into AE quickly.