There are a lot of sites like Freelancer and eLance where you must bid for project to get the chance to do them. Many people find this process incredibly frustrating, especially when you take a look at just how many others you are competing against. Freelancing sites in general do have a lot of value and there are some tips and tricks that you can use to improve your likelihood of winning a bid.
These are posts written by other people, whether they be friends of mine in the space, or hired freelancers or other outsourcing methods. I just categorize them as guest blogging posts so I don't have to defend their opinions :)