Building a small content management system

i just got a call from a friend about a color/home improvement company who like their website redone, including a cms for the various colors they’re offering.

since i’ve never done this before, i told him that i’ll look into it and call him back at the end of the day

i know just a bit of php, but since i got time on my hands, it wouldn’t be impossible to dive deep enough into it to get an acceptable site running…

what do you think? should i try?
is php at all the right weapon of choice for this?

basically i don’t think it’s a smart choice to participate in any project where i don’t have enough knowledge not to mess things up, but honestly… i could just very well use the money :-/