Eek! I'm in nearly the same boat as you, iamii.
Unfortunately for me, though, I was born and raised a Mac user.

I remain one to this day, and am typing on an iMac. However, I can see the benefits for both operating systems, unlike some on this board, and think it a good idea to have a PC on the side.
So I've been following this thread with great interest. All of the above links have been read through, and bookmarked. I feel like I know enough about the 'basic' physical installation to do the act, but I have a few questions for the computer whizes out there on TFP...
1 - When I got to the ending of the articles, it started talking about BIOS and a bunch of acronyms I couldn't begin to understand. It looked to me like a lot of command lines, which I know absolutly known. The thought of installing an OS through this BIOS terrified me. Is it simple enough that a complete newbie such as I could handle it, with of course some TFPers help? (All of my friends consider me a computer Guru™, so I can't turn to them.)
2 - Regardless of the BIOS thing, they talked of installing the OS with 'system discs', which turned out to be 3.5" floppies, I believe. Is this absolutely neccessary? I've grown so accustomed to CDs that I was hoping to not even install a floppy drive with the computer. Would that be advised?
3 - From what I understand of the PC world, there is basically Linux and Windows. From my ignorance, Windows is for the more casual user, while Linux is more user intensive... For this first PC, I don't want or need something completely bad ass. I'm not going to overclock, or be working Photoshop from this. It's just a computer to get the basics of building and the Windows world. Which operating system would be best for me? If Windows, which is what I was leaning towards, what version? Are there warez versions I can download, or should I just pay for it? My experience with Macs makes buying OS's very cost oriented... What do you suggest?
4 - Right now, I have no components, nor do I know much about them. I was hoping the TFP whizzes could come up with a summary component by component. Like I said, I'm a Mac user, and used to useing what I buy. Having 20 different choices for motherboards overwhelms me. If perhaps you guys could narrow it down to the two top brands for each component, or even individual things, that'd be great. I just need someplace to start, as I have no idea what to buy.
Cost isn't neccessarily an issue. I have plenty of money, but I'd prefer not to spend a huge hunkload (More than.. 500 or so, excluding monitor... is that reasonable?). Like I said, this be to serve a farked site or anything severe. I just want something kinda basic.
Now I understand it'd be in my own benefit to research this on my own to determine the best scenario. I will certainly be spending a large amount of time researching. However, with juvenile knowledge, I'd be easy to dupe, and a few helpful mentors would be greatly appreciated. I also thought some of you would get a kick and have fun.
iamii, I didn't mean to threadjack, and hopefully this leads us both to great computers. I'll certainly be listening to the info they give you, and attempting to absorb it all.
Thanks in advance.