Take a look at
Joomla. I was a complete noob to cms and I was able to set it up in very short order. It has a good user registration system and you can integrate forum boards, galleries, and what not - and set it up so that only registered users have access to different parts of the site. If you go to the site, goto the extensions section and check out all of the add-ons and things you can do with the site.
My site
http://www.bbpinlist.com is set up with joomla and has a lot of features and flexability with a relative low time investment. All free under open source.