To buy or to build?

[Qwann]

Alright MMO-Champion, I thought I'd ask for some help here, as I really have no clue as to what I'm doing around computers.

I've just started my senior year in high school, and I'm getting set and ready to head off to the University of Arizona next year, but in the meantime I've decided to take a plunge and upgrade my piece of crap computer.
Current Specs: (I'm reading these from my System Profiler so if I don't know what I'm talking about please correct me)
It's a Macbook from either 06 or 07, not sure.
Processor: 2.4GHz Intel Core 2 Duo
Graphics Card: Intel GMA X3100
Memory?: 2, 1G 667 MHz DDR2 SDRAM Not really sure if that's right so help me out.
Operating System: Mac Os X 10.5.8

I've looked at the "Help Requests" post that explains what components to include, but I either don't know what they are, or can't find anything comparable within my system profiler. Also, is there anything that I can do in the meantime to make my gaming experience a little better? I've heard overclocking mentioned, but from what I can discern that's got something to do with making your computer work faster but run hotter? Is this something I can do? Is it viable? What about cleaning out the hard drive? Does that improve performance?
~Anyways, I'm looking to upgrade from this MacBook. Right now I can quest/10 man raid with reasonable frame rates (5-15), but 25 mans and intense moments in the day in dalaran slow it to a crawl. I've also recently picked up SC2, but I'm doubting my investment because I've increasingly run into situations where I lose matches due to my computer not being able to handle the game on absolute bottom settings. I do realize this computer was probably not built with gaming in mind in any sense, and according to SC my graphics card isn't supported either, but I think I could do a bit better with more than 10 fps in basic battles and certainly more than 2 fps in much larger battles.
So, without further ado, I've got a lot of questions/points.
1. I'd like to buy a computer to be able to run my computer games (WoW/SC2) on more than the most basic settings, with more acceptable frame-rates (25-45), but there's a multitude of options available to me, and I don't really know where to turn.
2. I'm on a budget, I'm a student, with a minimum wage job with lots of upcoming student loans to pay off and lots of college expenses, so like everyone else out there, I'd like to get my money's worth. I'm thinking a budget of around $1200-1400. Just spending a brief couple minutes looking over this forum implies that building your own computer can tailor it more to your needs and be cheaper than buying a pre-made unit. So, what can you guys tell me about this? I really don't know much right now, but I consider myself a quick learner, and if it means I can save a few bucks and learn a bunch, I'd love to build my own. Are there guides to this? Guides better than others? Should I really just do myself a favor and buy a pre-made unit?
3. I really don't know my way around computers, but the jump from Mac to WIndows scares me. Am I really any more vulnerable to viruses/key-loggers? How about windows 7 vs vista? Any other tips? Can you build your own Mac also? Or can you just build a PC and put any operating system on it?
4. Many people these days have lots of doodads and additional options with their computer. How do you: Use multiple monitors? Hook up a computer to a Tv? What about monitors that allow you to switch inputs and watch TV that way? Etc.

Thanks for slogging your way through that wall of text, and any info that I get will be appreciated.

Tl;Dr I'm a complete computer n00b, but I'm afraid that if I buy a pre built computer that it will cost too much and be out-dated/ill-suited for my needs very quickly. Halp!

[Moobious]

1.) Doesn't everyone?
2.) That is plenty of monies for a nice gaming rig either through buying a configured system or buying parts. There are many guides. more on this later
3.) OS X is the most vulnerable OS out there. Most of the problems that people have with windows originate between the monitor and the chair. The OS has to be designed to run on a PC. There are options but windows is the OS with software.
4.) Most recent video cards have multiple output ports on them, you just plug more monitors into said ports. Of the multiple output ports on the video card most cards have an out put that will plug into a TV; some TVs have a standard computer input ports on them. Eh you lost me with that last one.

[vesseblah]

Your old Macbook can't be upgraded, except add bit more RAM. It would make overall user experience better but costs quite a bit.

Does the new computer need to be laptop, or desktop ok too?

You can get nice Windows7 based gaming desktop (including monitor) for $1000 or so if you do it yourself, and the bottom line depends on how much future proofing you want. $12-1400 is going to be enough with that route. Pre-built costs maybe $1-200 more and does not necessarily have the option for parts you really wanted.

Windows Vista is more or less dead and should be ignored. Getting used to new operating system will take time, but it's not impossible. Yes, there are more trojans, viruses and all kinds of other shit on Windows platform, but with some safe computing habits those are not going to be a problem. Currently Apple's Safari is the most unsafest web browser, and security flaws are patched slower on OSX than Windows. Macs cant be really built as much as you can click on checkboxes and order among certain pre-select models from Apple.

Multiple monitors are really easy nowadays, all desktop video cards have output to at least 2 monitors, so you just plug them in. Or you can use big screen TV as second (or even only) monitor as long as it's FullHD.

[haxartus]

I haven't been infected by a virus (except infecting myself for testing purposes) in more than 5 years. I'll see if i can make it to 10.
Of course some people get infected every day, but that's their fault. You'll have to build some browsing habits, like not downloading files from unsafe sources or not clicking on every link that you see.
I would recommend using Firefox with NoScript addon. The only problems with it is that the browser itself is kind of slow, and that won't be fixed until Firefox 4.0 comes.

[Aley]

1. While there is a lot about this to be found on the forums (you should really take a look at the framerate sticky ), i usually recommend getting a AMD Phenom X6 1055T combined with a decent videocard, a ATI Radeon 5750 should last you well into Cataclysm. Combine this with 4 or more GB ram and you should have a decent setup.
2. Try looking for some computer tweaking forums, i've heard tom's hardware is quite decent. Besides plain reading, i recommend disassembling an old / defective computer just to learn how it all fits together. It's way better to overtighten a screw on a trash setup than on your brand new setup. As a basic rule of thumb, try not to touch any pins (Especially not on memory / CPU), tighten screws, but don't overtighten. Don't try to force anything, if it won't fit try to look how it's supposed to fit.
3. Building your own mac is, sadly, not legally possible due to Mac OS restrictions. Vista is basically crap, you should really get Win. 7, as it's basically a mature, stable version of vista. Security is an issue, but getting a decent virus scanner (i personally recommend avira antivir) should be enough. Ofcourse you always need to be careful with keyloggers, but this also applies to macs.
4. Dual / triple monitors are really easy, when using a recent ATI card it's even got a wizard AFAIK. When using other / multiple cards you just hook them all up and position them properly in the Windows monitor setup. Be aware that only ATI supports Eyefinity, which makes it an awful lot easier to play WoW fullscreen on multiple monitors. Other options are possible, but are a huge PITA. I'm doing it, but it's horrible and requires third-party tools to work properly.
Hooking up to a TV is quite easy if it supports HDMI: you merely connect it and your PC sees it as another monitor. I've never used a real TV near my pc, but it should just see your computer as another channel, just like a DVD player.

[Dethh]

1. , i usually recommend getting a AMD Phenom X6 1055T combined with a decent videocard,

Why do you recommend AMD Phenom X6 1055T? It performs worse than its 4 core version for gaming.