Mambo, moodle, phpnuke, drupal are some of the well-known php “content management” packages. I once used mambo and moodle. Exellent quality and usability.
These open-source packages can help a lay person put together a website quickly. Compared to a from-scratch approach, a package offers, among other things,
* nicer web pages
* perhaps faster development, if the package supports your requirement
* fewer bugs, better tested
There are drawbacks.
* I feel you would have a hard time understanding the source code — dozens of source files, containing thousands and thousands of lines — before you can “hack” the code.
* you may realize you only need 1% of the source code to implement your requirement. It would have been far more manageable if you could throw away the other 99%. Not easy.
If you have time to search, see if you can find some bare-bones php “content management” mini-packages. If you find one, let me know.