must've been a rough day at work,
Thanks for assuming that I'm still at fault for your rudeness. You could (and should have) left that out. Do you want a response? I can think of a couple that I know you wouldn't like. I have manners though.
Please take a second and read the readme text file that's included within the zipped download. The warning and suggestions are there for a reason. You mention that you're new to PHP. Chances are WPMu is not for you.
If you're not comfortable editing PHP code, taking care of a complex webserver and database system and being pro-active about following developments of this project then run, don't walk, to http://wordpress.com/ and sign yourself and your friends up to free blogs.
It's easier in the long run and you'll save yourself a lot of pain and angst.
That warning is there for a reason.
The first thing your developer is going to do is make you sit down and work out what you want. Just pointing at another website isn't going to work and may get you into a fair amount of legal trouble. I would do that first before talking to your developer.