Woohoo, I'm the first to answer. I hope other people put their opinions in though, because I'm sure things are different all over the US.
1. What the hell is HOMECOMING ? Homecoming, at least at my school, is a week dedicated to school spirit. Every day we have a different theme to dress up in, which is completely optional. All of homecoming is, really. We also have Deck the Halls that week. There are four main hall ways in my school, and each class (freshmen, sophomores, juniors and seniors) have one to decorate based on a certain theme. It's a competition, but seniors just about always win. At the end of the week, there is a pep rally, a football game, as well as a dance.
2. Is school like Saved by the Bell ? Haha, I don't even know how to answer this one. We have different classes, we have lockers. At my school, we aren't allowed off campus for lunch (I don't know if they do that in that show...) and just about no one is that close to the principal. No little meetings and parties together.
3. What british tv shows do you guys watch ? Honestly, I don't think I watch any.
4. Is it uncool to be in band ? Well, the band at my school is really, really good. Like second in the nation good. But we still call them band geeks

5. What is a pep rally like ? Everyone gets into the gym, and the drum line plays, the cheerleaders cheer, the football players get introduced, etc etc. I didn't actually go to any because you had to get tickets for them, the school was so big.
6. Does everyone really hate cheerleaders ? I don't. Some of them are stuck up, but some of them are super sweet.
7. Explain the whole Elementary-Middle-High School system. The grades vary a little bit from area to area, but basically Elementary school is first grade to fifth grade. You have the same teacher all day long, and they teach you all the subjects. Middle school is sixth to eighth grade. You have different teachers for your different subjects. High school is ninth grade to twelfth grade. Also, you have different teachers.
8. Do you have sororities like Leagally Blonde ? Yep. Some of them are the stereotypical sororities, others aren't.