Photoshop, Fireworks (easy and quick to learn if you don't) and Flash helps, too, but not necessary.
Additional Info
I want to start working with a designer. I can design but I don't like it so much so I'd rather work with someone and find some jobs. If we work well together, we can stick together. You'd be communicating with the customer concerning what they want out of us and I can talk money with them (I'm good with the business management side of things). Then create a wireframe in Fireworks to approve with the client, and finally a full color, full detail PSD to be approved and modified as needed. I'll do the rest. I'd like to see some of your work, too, if you have any pertaining to web design.