If anyone is interested, I loaded up DokuWiki (http://www.dokuwiki.org/dokuwiki). Lots to configure, but it comes with excellent documentation and their forum is very useful.
I'm still in the process of tweaking it. There is no way to set permissions on individual documents, only on groups of members. So I'll have to setup each member as their own group, then set the permissions as to which docs they can access. All in all, with a little readjustment of what I want vs. what I can get, it's working.
I haven't tried customizing the theme yet. If anyone has done this and discovered any good tips, please post.