1. I'm sure you can find lots of gigs on Craigslist or through a recruiter. Through a recruiter, you'll probably find more jobs that want you onsite during the day, which will interfere with your real job.
2. Which leaves you with looking for freelance gigs via Craigslist and such. The majority of those projects will be from people with little understanding of what they really need, and even less money. As a result, you should be picky about the jobs you take. You need to understand their business model, not just their programming needs.
3. I recommend against making fixed-price bids on freelance projects. Hourly is much easier for you to manage, and keeps the client from feature-creeping you. It's fine to give estimates, meet their budgets, but don't fall into the trap of fix-price bidding on an undefined project! Yes, it is harder to negotiate and win an hourly contract vs fixed-price, but it is worth it. (You will get burned on a fixed price project: it will happen to you, as it does to all new freelancers, so here's my "I-told-you-so" in advance!)
4. Collections. Collecting payment needs to be easy, and often isn't. Do not deliver source code until you are paid. Have a contract stating that payment indicates acceptance. Show them frequent builds and let them see and use the software frequently so that invoices are not a surprise. When you don't get paid, stop working.
I also advise taking on an easy project to start. Make sure it is a slam dunk for you and get a taste for whether or not you want to keep doing freelance projects. Good luck!