Your best resource is this:
This is long but it covers all aspects of a big-company interview process:
- How to prepare
- Types of questions (spoiler: very comp-sci oriented)
- Why you might be doomed anyway
Important: And I know what you are going to be thinking when you read this: "This sounds like comp-sci stuff, but I'm interviewing for a UI position".
Do yourself a favor and don't think that!
I had a phone interview with Facebook last year for a UI position. I was asked a single question (it was a online-collaboration coding session): "Write an algorithm in any language to print the nodes of a Binary Tree in level-order."
I didn't get past that stage. The interviewer sounded positive with me, especially during the questions I asked him, so I have no idea what happened, but I know that I didn't blow him away with my speed on the coding quiz. I was completely under-prepared for that type of question.
Google's hiring process is going to be much like Facebook's. So is nearly any other 2000s internet star. Older companies are probably a bit different.
P.S. In case you needed it, more proof that Facebook has a very-Computer-Science-influenced hiring process: facebook.com/puzzles