Linux – Apache directory permissions for a company intranet

I have a company intranet that I have recently migrated from Novell to Linux. I am trying to set up user permissions and I am losing my mind.

There are a couple dozen departments, each with a dedicated directory in the web root.
There are also shared directories for css, templates, images, etc.

I want all users to have read-only access to the entire site and read-write access only to their department's directory.

What I have already tried:

• Set up a user group for each directory and assigned users to the groups as needed. Running into permissions and ownership inheritance issues.

• Created a test user and then created an htdocs folder in test user's home directory. Then created a link, renamed it to the dept. name, and dropped the link into the main htdocs directory. Read access is perfect but I cannot list the contents of that directory when using Dreamweaver or an FTP client from the htdocs root.

I feel that there is some simple-but-crucial piece of info I am missing. Selectively setting up read-write access to htdocs subdirectories cannot possibly be this difficult.

Any advice for a non-experienced user, used to Novell and IIS?