I have just started to do animations, but one trick I've found that helps tremendously is to render the foreground elements seperately from the background elements, then composite them in a program like Vegas. If your background is static, for example, there is no need to render it in every frame.

As noted above, rendering each frame as a still really helps if you run into trouble. I've also found initially that I was rendering far more frames than were required, so experiment with Poser's Key Frames control in the Make Move dialog.

Peace!