Building a computer is pretty straightforward and you'll have no problem finding online guides or books from a bookstore. If you know the basics of a computer and how it operates, then you probably don't even need to use a guide.
You didn't list your price range so I assume you are looking for the best of the best. For soundcards, get the SoundBlaster X-Fi Extreme Gamer for optimum sound, and a motherboard that supports the Core 2's, such as the Intel LGA 775 (Bad Axe 2) or an EVGA 680i if you want SLi. The Asus Striker Extreme would be ideal if you have the extra cash.