Jazzdude;
If you are using a printer, then 'dpi' has a meaning. If you are displaying graphics on a screen then 'dpi' does not have much meaning. If you want a (movie) width of 640 pixels then set that size in the dialogue box.
I haven't got A*L on this computer and I can't remember if you can set the f/s (frames/seconds) speed in the A*L dialog box. Maybe you can?
You can sent the 'quality' of the render in the dialog box. For moving images you don't need much anti-aliasing (this will speed up your renderings).
If you really want to play with movies at the very least pick up a copy of 'QuickTimePro' as this will help you edit.
Tip: if you are producing movies from A*L you may find it useful to save the images as a series of individual (tiff or whatever) files and then pull them together in a movie editor.
HTH - Stuart