Looking for some advice on a Golden Triangle Storage setup.

Good Afternoon,

I'm an IT technician at a school where we currently have a 600 computers and are now getting many requests to integrate our Macs also into our system. I've used Macs for a while and have tried and researched to get this query sorted but with no avail.

We have our students/staff log into the Macs with Active Directory authentication and then they access their windows folders from there. The problem we are having is with programs like Logic and other Music Technology related programs the allocated storage is getting filled up rapidly.

We have now bought ourselves an external hard disk for use only with Macs and we would like to have that allocated to users. So our ultimate goal is to have users being able to log into the Macs, access their windows areas and save their mac files to the mac only storage. We're not sure where to start and if we were pointed in the right direction we don’t mind researching and learning-by-doing if needed it's just the first step we're not sure of!

Server: MAC OS X 10.5.8
Macs: Most on Snow Leopard some on Leopard and a couple of staff on Lion
Windows: All XP except for a few staff on Windows 7

Thanks,

Josh