Broke guitarist looking to pick up bass

I'm looking to pick up bass but I'm a broke college student and my knowledge of what to look for in a bass is very limited. I don't need anything too fancy and I have some time to do some shopping around. What brands would you guys recommend that are both affordable and dependable? I don't really plan on picking up a new one, so I was also wondering where good places to find a used bass would be. I of course know Craigslist, but has anyone had luck elsewhere, such as flea markets or second hand stores?