Amazon's interview process is well documented in books like "Cracking the Coding Interview". Basically you will get one or two phone calls where an algorithm problem will be asked with optionally some behavioural questions asked. You will get the chance to ask questions to the interviewers here.
Then they flight you to an onsite loop interview where you'll have 4 interviews, including the hiring manager and the "bar raiser". These interviews are very similar to the phone interviews, with at least 2 coding interviews, design and behavioural questions depending on the role you applied for. After that you'll receive the answer about the process a few days later. People were very nice along the process.
In my case I got the offer :)
I prefer not to disclose the full questions for confidentiality purposes, but if you study "Cracking the Coding Interview" you should be good to pass it.