Was watching the video and got me really confused...Do I need thermal paste only if I have a heat sink or what? Also like the cable management part he rushed and I that got me confused too, also how did he get his GPU attached I was watching but he was blocking the view with his arm...These little things can make the video a whole lot better!!
As for the thermal paste, if you are using the stock heatsink that came with the CPU it will have some preapplied, if you are using an aftermarket heatsink some come with thermal paste, some don't so you may need to buy some.
From my experience and I have built well over 100 custom gaming computers, every cpu heatsink needs thermal paste. I usually do one thin line diagonally across the heatsink where the cpu and the heatsink meet, but I agree with Brett you need to watch the videos, there are hundreds on you tube dedicated to installing parts on your new system board.
Adding to what total just said about grounded, you need to be grounded when working on this type of equipment if you have money go to Radio shack get an antistatic strap put it on and attach the lead to the case, if not where a t shirt and keep your fore arms on the sides of the case. Stay away from rugs while working on the computer.
If you are interested in building computers I suggest finding whatever method of learning you prefer, whether it's watching videos, reading, or asking someone with knowledge the questions you have.
A good outlet that I used was youtube, there is a million videos to answer all your questions. Just do your research and take your time, don't invest your hard earned money and waste it by rushing and making a mistake.
there are lots of things that can be said but to keep it on track....... don't bash the guy for wanting learn. Everybody should soak up information from whatever source available before jumping in on something, especially an expensive endeavor.
if you decide to build your own don't stand on a rug in socks while doing it and wear a pair of sneakers or shoe. building one of these is not hard. You just need courage and don't be afraid of the hardware. It doesn't bite.
and don't plug the power supply into the wall until everything else is assembled and you're ready to run the machine for software installation.
-> The usual advice; read the manual / install guide; look at the parts, read the manual again and if everything makes sense and looks right - then go ahead with the install.
While you're waiting for delivery you can download the online version of the motherboard manual and start getting familiar with it. Same for the other parts you want to order if they have install guides or manuals available.