99designs.com: Put your project up for bid and people will compete to give you their best design. You only buy the one you like.
KillerCovers: If you need a cover for an ebook, DVD, etc, go to Vaughan at KillerCovers. He’s fast and good.
Odesk: At Odesk, you can hire practically anyone to do anything – your graphic design project, of course, but you can also hire researchers, writers, web developers, sales people, or nearly anything business related.
In graphic design, nothing is free, and unfortunately, little is cheap. Here’s where I recommend you go.