Are there any public schools to avoid in Melbourne?

I have an 11 yo daughter and 13 yo son (will be having birthdays in a few months) and shifting to Melbourne in Aug/Sept. Schooling is obviously a concern. I am happy that they will thrive in most reasonable schools - both are bright although daughter needs to be challenged a bit I reckon. I really want suggestions for o.k to good co-ed public schools and any that are too large or have bad reps and shoud be avoided...
Thanks!