I'm assuming you have a clear vision for your product/service. You're going to have to take the lead on owning the product, there's no getting around this. There's almost no chance you're going to find a co-founder that's going to handle the product/development, etc while you focus on marketing. I've tried and each time has ended badly. I advise against co-founders unless you know the person well and have worked with them in the past.
Here's the key to getting something developed in as little time and effort as possible. Start with the design. What the user will see when they come to the site. Don't worry about the backend at all.
Search on Dribble for designers - they don't have to be front-end developers. Actually better if they're not (cheaper). For more affordable quality designers, search eastern europe/russia.
Contact a bunch of designers, see if they're available and what their rates are. See how quickly they respond, etc. Select 3 or 4 and give each one the same first task. It should be something that takes 2-3 hours. It could be taking a sketched mockup, polishing it up, etc. After each one has completed this, you pick the one you feel was the best.
A lot of good designers know good front-end developers. You can find one through the designer. If not, you can do the same process on odesk for both front-end and back-end developers.
This is the process I use after a lot of trial and error, and it works the best for me.