Permissions vs Access Masks

[kersti]

OK, can someone please explain to me the best way to do this - I have a feeling it's a combination of the permissions and access masks...

I have a large forum, many sub forums. It's a craft based thing, so for many local groups I have private forums. Setting up permissions for these groups is a nightmare.

I want to be able to set up a new usergroup, add in their forum and set their permissions to read and write there but not see anything else. When I do this, I want the other groups to not see the new group.

What's the best way???