I've used Peopleperhour.com to build my career. It has a good community and isn't a "php-farm" like the other freelance sites (though it has been going downhill a bit lately). I still would highly recommend it but you will need a good profile before you start getting jobs. Though, once I did have a good profile, potential clients kept inviting me to bid to all sorts of jobs, so it's not hard to get good income out of it once you get started.

I don't use it much anymore since I found a full-time job, but it kept me in great shape for almost four years.

Below is an affiliate link if you're OK with it.

https://www.peopleperhour.com/site/register?rfrd=145291.1