PHP

I've been asked to re-do my school's webiste, an although I'm doing most of it with Frontpage, I would like to include a fourm. Can anyone tell me what I would need to learn to properly set up and administrate a fourm using the likes of www.simplemachines.org ?

i want to make an operating system because MICRO$OFT (note the dollar symbol - i am so 1337 that i diss windows) and *NIX suck.

i'm kinda new to HTML. any ideas where to start?