How do I make a dock for my WAD screen?

[Mr31337]

I'm not sure if this is the proper forum for this topic. Let me know if not.

I want to make my own docks and maybe some other things for my WAD screen, but I'm not sure how. I have Photoshop CS2. When I create a dock the way I want it, with the transparency I want, I try to save it but I'm not sure what format to save it as. Is there a tutorial or something so I can learn how to do this stuff? Thanks!