How can I find the personnel to start a website to compete with Craigslist?
Congratulations on all your prior successes!
While this isn't strictly a technology-related question, I'll answer it to the best of my ability.
The best thing to do is to write job descriptions for all the people you think you'll need for the project you're planning. You'll need graphic designers, UI (user interface) designers, information architects, programmers, QA (quality assurance) testers, support staff and possibly a copywriter or two.
Each of these areas of specialty has affinity groups online. For example, there are some great freelance developers at odesk and eLance.com.
Take the time to get clear on the types of people you'll need and then use a search engine to locate their affinity groups online. Searches like "freelance graphic designers" will turn up some good ones.
Also, it's ALWAYS a good idea to get recommendations from trusted colleagues who share the same values as you.