MGoAdvice on car subwoofers

I want to put some subs in my Toyota Sequoia but I don't know what exactly to put in it because I know nothing about car audio. I have been thinking about 2 12" subs but the guys at Best Buy said that would be too much. I like to listen to rock/rap/hip hop so I was just wondering if there are any car audio gurus out there that can help a fellow Wolverine out?