This is one of them. But check out the mechanics sub-forum as well.

If you do do it yourself this is just not how it will go. You'll keep finding nicer bits here and there, and it will be so much fun to put them on your bike and try them out, and hey, I put that BB together way better than the last time! Then you'll stumble across a dirt cheap frame, and hey, I need some **** to make this thing go, and so you stumble across the bits, and oh, that's how you adjust a headset, well I better re-do my Soma too! It doesn't end, n+1 and all that.
Do it your self. If you're unsure of anything get a friend or a shop to check it out, don't kill yourself because you read on the nets that it was done like this, and even though it feels unsafe, I did it like it said to on the nets. It's totally worth riding a bike that you built yourself.