First, decide what kind of design you actually need. Write a really detailed design specification of what you're looking for. Don't worry about what programs the designer will use or the details of how they will accomplish the job. Just think about the end result and what you want the designer to actually deliver.

Remember that there are many kinds of design, so it's helpful to think about what core value you're looking for. Do you want something that's based on an existing corporate identity, or is this something built from scratch? Will you supply excellent copy, or will the designer have to write it (or bring in a writer)? Is this more about "how it works" or making some existing functionality pretty? These are just a few questions to think about; the more "thinking" work you do in advance, the better the results. (If you find a designer who can help you think through all these topics in detail, then you'll really be cooking with gas.)

Next, determine if you want to actually pay; or if you want to pay some pitifully small amount. For the latter, post your design spec on Craigslist. For the former, locate your local chapter of the AIGA and start networking.

Here is a good place to start! I am a front-end guy here with a foundation in design. I am a bit busy at the moment, thus unavailable, but there are many more like me that frequent the board. Good Luck!

How about http://99designs.com/ ?

You could choose the one you like best, and approach the designer for additional work.

Unfortunately the result is usually pretty crappy.

I'm looking for great designers like those who advertise on Sortfolio, not just a "cheap" one, which seems to be whom 99designs is targeting.

I can help out. http://masswerks.com is me.

UI designer over here! o/