<font color="DAB9E8">Does this vary from school to school? I'm wanting to take 9hrs... would that be acceptable, or is it just crazy?</font>

McGill lets you take 3 credits for each month of summer school, so 9 it is. Each course lasts 1 month. I'm taking 6 this summer.

At most schools, you can usually only take 2 classes during each summer session (some schools have more than one summer session)...so, it would depend on how many credits each class is worth.