I saw that Tamora pierce was suggested and i was gonna say, that's a little bit over the age group your looking for. Not by much though.

But also thinking. i have no idea what to suggest because i don't know what age group books are supposed to belong in. i always tended to read ahead of my age group...

I suppose Holes mgiht be a good one.

okay so i thought of one. and i'm not sure what age group it is. but i think 9-12 ish was when i read it.
the half magic series. i can't remember who its by. but they're really good books.