Start becoming technical yourself. You'll begin to learn what 'great programmer' means to you, and will have a much better sense of what type of technical talent you need. I think this is true even if you don't progress very far down the path towards becoming technical -- at least giving it a shot will count dramatically in your favor.

Just write what you need into the ad. No requirements for buzzwords.

Get someone -- a friend, a consultant -- with domain knowledge and preferably hiring experience to help write your listing, screen and interview your candidates. Make sure your qualifications are spot-on, well-targeted and appropriately descriptive.

In addition to this good advice, make sure you give some indication of what makes your project interesting _to the programmer_. Only another good programmer can tell you what this is.

If it's not an interesting project, getting a good programmer to jump on it will be hard.