You guys are so nice. Thanks.

I fooled around with it some more.

LM, it's pretty easy to do this stuff, esp. if you do it half-assed like I do. You just make dif. layers in Photoshop, then jump to ImageReady (which is a branch ap., under the edit menu), go to the view menu in IR and get the animation palette, and use the palette's submenu to make frames from layers.
Theoretically that should place every layer into a dif. animation frame and allow you to fool around with the timing of the frame. I found I had to dick around with the frames and layers, though, to get certain layers in the frame sequence I wanted. (The directions I got online were basic; I could find something more specific online or pull out a manual to solve the problem, but I've been too lazy to do that. :p)
The animation palette is really cool. It shows you the whole sequence of the frames, lets you diddle around with each frame's timing, and has controls so you can play through the sequence and watch your file become animated.

In any case, at the end you save the whole mess using "Save optimized as ..." and select images only. This results in a gif.