Certainly, you can make graphics in Photoshop for your After Effects compositions. In fact, you can import multi-layered PS files right into After Effects. Creating a graphic for the web has the same basic principles as creating a video graphic, however, you would probably use a different file format for export. For example, you would use a PSD or TIFF file instead of a GIF. With a PSD, you could use the layers from the original graphic right in AE.
Hope that helps!
Thank you Kevin. I'll kinda figured that would be the be the steps but wasn't real sure. Once I get going in PS, I'll better understand how to do things.
Wow, lots to learn.
Fantastic! I have a feeling you are going to love After Effects. The more you use it, the more you love it. Come back with any other questions you may have.