Checkout http://99designs.com/ if you're looking to get a simple logo designed for cheap.
Personally, I recommend learning yourself. Rudimentary graphic design is a pretty useful skill to have. Gotta say though, it can be a little frustrating. Unlike coding, where most of your time is spent building and adding, design requires constantly trashing and starting over, so it always feels like you're not making much progress...
It took me a whole day to design the logo for Taskforce (https://www.taskforceapp.com/) for example.