My, such an informative response. Just what a forum is supposed to be for.
Anyway, for motherboard you may get an Intel BLKD975XBX2KR, while there are others from ASUS, MSI, Abit, Biostar, as well as other manufacturers from which you can get reviews and references I prefer to use Intel motherboards because they get the best compatibility and performance from an Intel CPU. Besides, you get an extended warranty from Intel if you use an Intel mobo, CPU and heatsink as far as I know.
There are various motherboard options there with various modifications and overclocking options to obtain more performance but if you don't know what you're doing you may end up burning the board or the CPU or have stability issues. Overclocking is at your own risk but since you're a first time builder I recommend that you don't mess with settings just yet. First step before aiming for modifications is to get the thing working.
You can find guides to build your own computer here:http://www.buildyourowncomputer.net/learntobuild.htmlhttp://www.sharkyextreme.com/hardwar...uild_computer/http://www.techpowerup.com/articles/other/144
Just a few I found by using Google (it is your friend). However, if you're not comfortable with building computers or have problems, you're on your own. Nevertheless, individual parts manuals have guides on how to use/install these parts and provide some troubleshooting steps.
For first time builders it is better to obtain some experience first, have someone qualified to help you or even have someone build it for you and pick the parts yourself.
Of course, its fun to build your own computer and see it turning on and getting to work. Just be careful at what you're doing and, yes, and every first time builder could face those first quirks when building a system as in why it doesn't turn on, how much paste to use, which cable goes where from the mobo to the case,etc, etc, etc.
That would be my first build-it-yourself advise. Have fun.