Motherboard Replacment info ??

[GameBreaker]

I bought a new computer just about a year and a half ago. I actually had it built for me. All the parts were guaranteed for a year. Well, it seems that my motherboard is now shot. I was having a problem with it turning off within 30 seconds or so of booting up. I brought it to the geeks at Bestbuy and they said the motherboard is no good. They dont carry or replace motherboards.

So, what I was thinking is that I will go to newegg and purchase the identical motherboard that I originally had and then just install it myself. Only thing is that I have no experience in this type of thing. Can anyone give me any insight into what is required or maybe post up a link to a tutorial.

Any help or advice at all would be really appreciated. Thanks in advance.