It's a large enough place to have many microcultures. Geo (Maps, Earth) is totally different from, say Android. YouTube's culture is nothing like Search and GMail's. And so on. So after you join, go meet other teams and get to know the big picture. Then, you can seek a transfer to wherever you think you'd best fit in.
This is always good advice whether the offer is from Google or a Big Bank.
Talk to the manager, talk to your coworkers. Once they give you the offer, their job is to market the job to you. Use that as an opportunity to interview your future coworkers. When I was considering finance job, I've even gone as far as asking the future coworkers to implement different algorithms and/or talk about their system architecture. If it was too crazy, it was an immediate sign that I won't be happy there.