I've got ads posted on Monster and JoelOnSoftware for a .NET programmer at a Salt Lake startup. I'm getting spotty results. Where does everybody run ads?
Go to your (local) user groups where your flavour of developers like to hang out. You immediately get a feel of who you would like and what their availability is like.
I would suggest joel Spolsky's book on hiring tech folks. He mentions several methods and, although i"m only on page 30, (1) I like Joel's style/approach to most things, and (2) the first 30 pages made sense to me. it's called "Smart and Gets Things Done"
I am having similiar results trying to replace myself so I can work full time on my project and getting no serious bites. Next step is to try community college job boards...
Craigslist is such a gamble. I've found that it's been mostly a waste of time. The way, IMO, to successfully use CL is to use an RSS reader that allows you to define "watches"/"alerts" (like FeedDemon). Create watches for the popular terms you are looking for and then subscribe to CL's resumes board's RSS feed. The more specific you are about the terms you want, the less clutter you'll go through. Putting a watch on "Windows XP" will get you nowhere; putting a watch on "Windows 2008" will find you an early adopter, for example.