How can I find a smart, reliable, experienced web programmer who's easy to work with?

I have a big web project, potentially huge, that I’ve been asked to design. There will be several aspects of this site that are beyond my abilities as a simple designer – database-driven stuff like job boards, a bulletin board (although this could be an off-the-shelf component), advertisements, streaming video, and more.

Is there a good online directory or referral system anyone knows of?