Help with linux / apache / php

Hi all, I'll apologise right away - this is more or less completely off topic, though it is remotely connected with PHP (so that's my excuse). At the moment, the company I work for is hosted on a co-located server. We have one main domain and many sub domains. Here's how they are (roughly set up): www.mainsite.com www.sub1.mainsite.com www.sub2.mainsite.com www.sub3.mainsite.com www.subn.mainsite.com The document trees are like this: /home/mainsite/www // main dir /home/mainsite/www/sub1 //sub 1 /home/mainsite/www/sub2 // sub2 (etc) We have just (in the last month or so) leased a cobalt raq all for our own use. Great. However, the sites using this box are setup and maintained using a web interface that comes as default with the box. when setting up sites (subs or otherwise), it adds sites (and you have to specify users for those sites) with directory trees like this: /home/sites/site1/web /home/sites/site2/web (etc) Obviously, this causes problems (like for the php scripts that are running on the current setup, where files are included / required as a part of the main directory, and out of the document root (/home/mainsite/includes might be an example)). So, I'd like to learn how to use linux (bearing in mind that I have very limited experience of unix based systems). I can perform the very basic commands, but would like to learn how to use / mainpulate the box through shell access rather than over a web interface (which ultimately, I'm assuming, will give me more flexibility - for example, I'd rather know how to install the latest version of php onto the server following the installation instructions than to attempt to do it through another medium). I've bought a couple of books and hope to delve into them in the course of the weekend and the next few weeks to come. I'm assuming that one of the first steps would be to install linux on my home machine and get a feel for it (currently I'm running windows.... ouch). So, here come the questions. Where can I find the latest version of linux? I have had a brief look at freshmeat.net and linux.com, but didn't find any download sections (I didn't look too hard, for reasons soon to be explained). If I install linux, can I still use windows as a secondary OS (perhaps running over the top of linux?) If I can run windows as well as linux, am I best formatting my main drive, installing linux, then windows? Is the httpdconf file one of the main files i need to confifure for sites, or are there many others (I've read a little about setting users up in vi and will read more on that, but are there mounds of files that you need to configure when setting up a new virtual site?) I'm sorry about asking what's probably obvious to most of you, but that's part of my reasoning behind asking on here - most of you will probably be familiar with this stuff. Another reason for asking here is that I don't know of any other relevant alt groups. I'm sure these questions have been asked many times before, but it really has been "one of those weeks", and I'm about fit to drop dead of exhaustion (not your problem, I know, but the sympathy vote might work ;)) - I've had a quick look through the archives and other sources, but the mounds of text that surround the basic questions I'm asking are (in my dazed state) making me even more dizzy. Lastly, thanks for reading. Any advice any of you can give, or any basic pointers you might have, are greatly appreciated. Please cc any replies. Thanks and goodnight, James