Ok so I know very little about computers. Right now I dual box on a dell xps 1530 laptop. I want to learn about how to build a decent multiboxing desk top. So I have some questions for anyone with a few moments to teach a noob. Kinda asking for a crash course in computer knowledge.

Whats a good graphics card? and how can you tell?
What should i get for a processer if i want to 5box?
I know a motherboard links it all together but are some better then others? and if so why?
Memory for the computer how much?
If I missed anything else that would impact multiboxing?

So basicly my Goal is to 5box on one desk top with almost no lag and high graphics. And priced as cheap as possible. I know most systems to get them cheap you gotta build them yourself. So I am seeking out the knowledge on how to do that.

Thanks in advance.