This is a slightly more general answer, not just to your specific situation.
Practice, practice, practice.
There are basically three types of questions in interviews:* data recall, problem solving, and stories.
Data recall is "what does the transient keyword do?" You know it or you don't. You prepare for this simply by learning throughout your career.
Problem solving includes questions like "how would you architect...", "what technologies would you use...", brain teasers, etc? You prepare for this also by learning problem solving skills and coding skills throughout your career. You can also try practice problems to get a sense of what they're like and to build up your confidence. (Tip: remember to always talk through your thinking, getting the right answer but now showing how you thought about it can be worse than getting the wrong answer but showing good clarity of thought and problem solving skills.)
Stories are the open ended questions, e.g. "tell me about yourself?" "what's your ideal job?" "what are you weaknesses?" You can find many of these questions in book or online. The way to prepare for this is to practice, practice, practice. Start with 2-3 questions and then add to your repertoire. Have a short answer (15-30 seconds) and a long answer (60-120 seconds). Practice your answers; I usually practice then in my head when in
shower, when waiting for the subway, etc (whenever you have a few minutes to kill). Much like public speaking you just need to rehearse your answers over and over until they few comfortable; but also like public speaking you don't want to memorize it
word for word or it will sound rehearsed.
Finally remember the airport
test, an interviewer considers the question:
if I was stuck at an airport for 6 hours with a co-worker which of these candidates would I want to be with? Preparation for this is easy to understand: be personable. You can't prepare for this, as Master
Yoda teaches, "do or do not, there is no try."
Henry is right that
you should do your research about a company, along with thinking about the job you want, and then ask questions to see if it is indeed what you want.
Vikram's answer is very astute. The best thing that ever happened to my interviewing skills was to give interviews. I try to make sure those who work for me always get to interview others since it really helps teach good interview skills (as well as serving to make sure the team gets the candidate they want).
--Mark
*This is an oversimplification but it's a good approximation.
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Ya, sort of, i start preparing when i get call... cause preparing in advance leads me to forget stuffs by the time calls come 
Anyway nobody shared their exp till now.. 
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