How do you have yours layed out in regards to available space and the space you use?

Alot of our systems were implemented after the disk space was allocated from the iSCSI but in the summer i should have the oppurtunity to expand space and make everything alot easier to work with, at the moment we have a single 800GB storage drive which has: network programs, staff work area, shared teaching resources which kids can access and teachers write to, home folders and our hidden program installer share all hosted on

Naturally the problem with this is that the home drives and teaching resources/staff work area are all hosted on one drive so quotas take in to count everything people but on the latter shares (one teacher appears to be using 109GBs - granted his home drive is 30GBs which is stupid mind you, but it's taking into count what hes put on there everywhere else)

How have you got such storage laid out? or how would you suggest i did ours from what i've put above?