I was scared out of my mind putting the thing together and really had no reason to be. No fear really. With ATX cases, power supplies and software configured motherboards theres really no room for screwing things up. Everything will go off without a hitch. If you need help, post a message to your DAW mailing list or newsgroup.
Most people are glad to help.
Once your system is put together light that baby up. Get Windows installed and whatever other software you have loaded. Start recording with your new 24 bit soundcard and your favorite DAW software and enjoy. But if your like most of us you will encounter errors, lockups, and hardware compatability conflicts. All of course can be quite frustrating.