My friend mentioned that there is a simple way to modify what users see in the admin sidebar based on their user role. I have a large number of custom post types, one for each user, and I need to limit these users (currently given the role 'author') access to only their own post type and the Posts (not even Pages). I also want to hide Widgets from them. Is there a bit of PHP I can stick in my functions.php file to accomplish this easily?
This might help you for what you are looking for.
To anyone else having the same problem as me, I used the Role Scoper plugin, which is recommended by WordPress on their page that describes user roles. It has a very simple UI, and is easy to install and use.