Domain users with shared/owned folders

I need to manage a Windows 2000 Advanced Server domain with 500 users.
The users are grouped (from 10 to 20 users in a group) and need to share a folder for “My documents shared” for every group and have his own (not shared) “My documents not shared” folder everyone.
Every user need to acces (read and write) to his group shared folder and his own folder (not shared).
I prefere that the two folders are in “My documents” on Desktop, for simple access.

What is the best solution for manage this? I need some extra stuff or Windows 2000 Advanced Server has the tools for this purpose? What is the right aproximation?

Thanks a lot

Josep