No need for a .psd
Key to designing is exactly that, designing.. with your own touches and expression. It takes practice to learn certain things, so it may be bumpy at first but you'll get better as it goes. You can also stop by Whiskey's Graphic Designer Resources topic and find resources there such as Brushes, Patterns, Gradients, etc and virtually anything you need in the world of Photoshop and more.
All you need to begin is;
Signatures must be 500x150 (keep the kb's in somewhat a reasonable size)
Avatars must be 100x100 and 100kb or under
Not sure if you're a PBM, legit new member or not.. but welcome to the GFX Section. Stop by the Rules & Guidelines if you plan on helping out with requests and get familiar with them.