I have an "online community" site in the works and I'd like to know what is the best way to handle these features:
Each user will have his own profile page where he can
upload a picture and other files. I would also like this page to be editable by myself so I can easily add a banner, button, etc.

The site will have forums as well.

On a users profile page, there would be a guestbook of some sort where people can post comments.

Everything will be tied together so that whenever a person's user name appears in the site, it is linked to their profile page.

I hope I made this sound clear. I'm not sure whether I should use Php with mySQL or what. I'm not sure where to begin. Any help is appreciated...Thanks!!!