Dynamic subdomain rewriting

Hello, I just installed wordpress for the first time on my local machine. I’m setting up a brand new site for my gaming syndicate, I am adding blog capability and switching my forum software from SMF to bbPress.

I have many a question regarding all of this, and instead of spending extremely valuble time(these days I sometimes pay people to drive me places so I can work on the way) looking for the information myself I figured I’d ask around.

I need to be able to use mod_rewrite so that one could type in user.mydomain.com and it will go straight to their blog. I unfortunately have no idea how to do this. I’m not sure if I actually need root access or not and if I do I’m prepared to make the switch from shared to VPS. I’ve found a few documents that sort of say how to do it but all they really do is quote their code without explaining how it works, and I can’t figure out what the lines mean and each “quote” of code is different. I imagine I’m making this a lot more complicated then it really is, too. xD

I was also wondering if anybody could direct me to a document that explains how wordpress and/or bbpress has their theme system set up? I will need to integrate it all with my main site so it doesn’t look like they are going to a different site.

Thanks a million to anybody that can help me out 🙂