B.M.
My daughter is just finishing up 4th grade, so I can give you a girl perspective. She is in a Montessori curriculum public school, so it may be a bit different. However, 9/10 year old girls I think are 9/10 year old girls any way you slice it!!!!!
So, she and all her friends are reading the Twighlight books so I would read all 4 books in the series over the summer, if have time. None have seen the movie, but they started a lunch book club and every Wed she and a bunch of her friends sit at this one table in the lunchroom and talk about the books. The teacher let them have a Twighlight day - they separated the class into "team Jacob" and "team Edward" and everyone brought in their fave twighlight stuff and for an hour did basically a 'show and tell'. The whole class had fun - even those who had never read the books.
I think this is the age where they really need to become independent, but it's hard, because they are still so young. But socially, this is the big year of big changes. Lots of girls get bras this year, some started their periods and most of the girls in my daughter's class started to shave their legs this year.
Also - know who Justin Beiber is, but don't try to be too cool..... overlook that they have pics and posters of him, but don't have any yourself!!!!! Hannah Montana is out, babies watch that show (but they secretly still watch cuz it's the last year). Fineous and Pherb is good at any age and will be forever!!!! DON'T let them actually do the single ladies dance (cuz it's inappropriate to move that way when you are 9) but let them sing the song!!!!!!
My mantra is "notice and mention, but don't make a big deal". I find that attitude gets me way further with my daughter. I think the best advice would be don't treat them like kids, but remember that (at heart) that's still what they are!
I think this is a great age (it's been my most favorite since she was 6). But it's also tough, cuz the attitude starts in a MAJOR way and the cliques start at school and then feelings get hurt etc etc.
Good Luck!