Oh I definitely did all the same things anyone else had to do.
Basically you do a phone screen. Then you come in for a day and you sit through 5-6 45 minute interviews, each of which involves whiteboarding through a problem. You're asked questions, most of which are probably way harder than they need to be, and you're expected to write and talk your way through it. Talking through your thought process, asking questions, and considering edge-cases is key.
If you want to study for one, I recommend going to http://www.geeksforgeeks.org/ and trying to solve some of the problems there, then looking at the REAL answer, and trying again. Just keep practicing like that until you have most of the patterns memorized. It's sort of fun anyhow.
Just remember, the person interviewing you DID NOT come up with whatever binary search or sorting algorithm you're answering with. They had to memorize it just like you. They're only as smart as you are.