Step 1 : Find the right partner

Unless you’re a rockstar programmer who gets business and user experience and product and everything else — in which case I’ll hope you’ll let me invest — you’re going to need a partner. If you’re a developer, you’ll need a product partner with good business sense. If you’re anybody else, you’re going to need a developer (at least…depending upon your technology background, you may wish to start with a product partner and have that person find a developer). Now, this next line is important so I’m going to use all caps for it:

FINDING THE RIGHT PARTNER IS THE MOST CRITICAL AND IMPORTANT STEP YOU CAN TAKE FOR YOUR STARTUP.

I speak from personal experience here (as previously mentioned, I’m starting a company). If you fall in the “anybody else” category and you have a decent understanding of technology and what it takes to start a company, you may think you can just find a development shop in the Ukraine and be good. I strongly advise against this…you need someone with deep technical experience on your side, even if they’re a friend doing you a favor and not full-time on your idea. You may quickly find, however, that you wish this friend were full-time on your idea. I could go on and on about how important I think this is, but instead, let’s talk about how you find this person (warning: this might get ugly).

1) Tap your network — and I mean everyone. It’s okay to send a mass email every once in a while…this is one of those onces.
2) Job boards — and I’m not talking about Monster. Doostang, YorZ, your alumni job board, the job board of a college/university in your area, LinkedIn…think about where your co-founder might be looking for a gig (chances are, they're at a big company)…be where they are looking.
3) Select websites with contact information for developers — I told you this might get ugly. If you can’t find who you’re looking for with (1) or (2), start contacting individual developers that fit your criteria. It’ll be slow and cumbersome…but you need to do it. If you're looking for Ruby On Rails developers (and you should be, even if you don't know what that means), check out jobs.rubynow.com and jobs.37signals.com.