template system suggestions / content management?

Okay, I asked this question in 'general', but was met with deafening silence, so let me rephrase it here. I'me trying to figure out the best approach to take to build a site that will allow form-based creation and maintenance of individual webpages, with the user providing set content areas such as a text blurb, a local img source to upload, a title, a category, etc, with the form updating database tables with the individual content items. After that, the pages show up in the proper areas relative to navigation categories, etc, as the navigation links, individual pages, etc. would be generated from database content. I've looked into phplib a little, seems like it would do the job but: 1. it appears to be lagging behind PHP4 2. I'm still a newbie when it comese to PHP So can anyone suggest an existing open-source content management / template framework system that I can extend or at least learn from? Or any other from-the-trenches anecdotes from someone who has done this would be helpful. Best regards, Andrew