[georgeorwell]

Craigslist, phone calls, a camera, and enough cash to secure a lease. Depending on how picky you are, finding the listings isn't the bottleneck, it's going and visiting 30 different places.

Sometimes walking around outside in the area you want to live in works. Sometimes asking friends on or off of Facebook works.

[rachelmaesmith]

I agree! If your friends don't know of any openings, Craigslist might be your best bet. I recommend setting up multiple viewings (at least 4) in the same day. That way, as you walk or travel from place to place you not only get a vibe of the neighborhood, but you might run across other for rent signs. If you have the time, I suggest you stay the night in the neighborhood you're considering to make sure it's not too loud/busy,etc. At least check a crime map!

Sometimes there are city-specific rental sites. If you're in San Francisco, this might help: http://rentsfnow.com