Most of this technical discussion is way beyond what I do, but I've built several basic computers and here is some "beginner" advice.
Take your time and be very methodical. Don't force anything into place and don't overtighten screws or connectors. Most components will slip or click into place easily. If they don't, stop and reevaluate what you're doing. Follow all of the steps in the motherboard manual carefully for making connections and jumper settings. Double check everything before you turn the power on.
It really is not very difficult as long as you go slowly and carefully.
