I am contemplating taking in just B/A kids. One of the things that I was reminded of was that these kids, during the school year, just sat in a desk for 6 or so hours. So on school days, I would say have scheduled activities or lessons a little fewer and far between and allow a little more "free" time. Or large motor activities, outside or what have you.
As for during the summer, I just googled "school aged kids activities" and found a bunch of great sites.
I find that kids that age seem to like "science" type stuff. And you can find tons of experiments using common household items. I suppose part of it will be determined by the group you have, too. Some of them are happy to do crafts all day long. Others get antsy a couple minutes in.
Good luck!!