Certainly be prepared and research the company you are interviewing with. Websites like glassdoor.com have reviews of a company by it's employees, or former employees, and can provide a lot of information about work conditions, management, and even what their interview process is like. I used this method when I landed an interview with Schlumberger to find they have a very unusual 2nd round interview. So when I got the 2nd interview invitation, I wasn't surprised at what they put us through and was able to breeze right through it.
Also, Silence is acceptable after a question while you formulate a response. I'm not talking 10 minutes of silence with a blank stare, but a brief pause while you form a solid response is acceptable and shows you thought through the question and didn't just blurt out an answer or stutter and stammer your way through it. That said, if you do have a ready response, answer the question and keep the interview moving along. Absolutely have some questions ready, and if you arent sure what to ask, google is your friend. Reserve compensation and benefits questions for the 2nd interview, unless they bring it up. There will be time for negotiations after they are convinced that you are THE candidate to hire. Try to let them initiate negotiations and make the first offer.