Help creating a file library system

There are several content access modules available that will help. You can restrict access by role to taxonomies, for example, which sounds like it might work best for your purposes. Tac-lite does a good job on this score.

Not sure about searching inside compressed files. Sorry.
----------------------------------------------------------------------
http://classicvinyl.biz
http://music.bwv810.com
http://davidhertzberg.com
http://association.drupal.org/user/1207

I am a writer, researcher and solo drupal freelancer

Files can be managed best by managing the nodes to which each file is attached. The node can also hold some information about the file.

To upload the files as attachments to nodes you can use either the core upload module or install the cck + filefield modules (especially if you want to theme and present a file's info with a standard layout in its node).

To control access to the files, you need to use the "Private" download method (in /admin/settings/file-system) and store the files outside your web root, so that they don't have an URL unless Drupal gives them a virtual one (it will look like /system/files/filename).

Then, you can tag the nodes with categories (taxonomy module) and install an access control module, so that only user roles who have permission to access the node will be able to access the file.

The categories can also be used for listing tables of files, with the help of the views module.

A couple of other handy modules are http://drupal.org/project/uploadpath (if you use the core upload module) or http://drupal.org/project/filefield_paths (if you use filefield), for storing the files to a subdirectory structure according to some rules.

I don't know of any existing solution for handling zip files.