There are pretty easy to follow videos now on the net, some of which show parts assembly and OS/Driver install. The new parts are more complex in some ways, but the nice thing is the Motherboards now auto detect the parts you've installed. Plus their BIOS is navigable via mouse now instead of just keyboard.
If you don't plan to overclock there are only a few settings to worry about in the BIOS, like XMP RAM profile to make sure it runs at it's rated speed, AHCI setting on storage devices because most are SATA III now, and then the usual Boot Device Priority where you choose which device the system prioritizes on bootup. This you need set to the DVD drive when install W10 from disc.
The physicality of assembling parts is pretty easy though. It only takes putting together 7 or 8 parts, and all the electrical plugs only fit one way due to the way they're shaped. It's not even really that hard to apply thermal paste and aftermarket CPU coolers, and most have fairly easy to follow instructions.
Here's a couple of assembly and OS/Driver install vids so you can see what it's like.
Assembly
[video="https://www.youtube.com/watch?v=VIF43-0mDk4"][/video]
OS/Driver Install
[video="https://www.youtube.com/watch?v=4zAdwedmj1M"][/video]
One thing I always highly recommend, especially for first time builders, is making a partition on your OS drive just for the OS and any drivers, etc that don't allow alternate install paths. That way when you need to reinstall the OS for any reason, it goes a LOT quicker because you don't have to reinstall tons of program files. This is easy to do during the W10 install. Before actually installing the OS, it will ask which drive you want to install on and on that screen it also lets you pick the size of the partition. 40GB is s good comfortable amount of space for OS and anything else that has to be installed on the C: drive, just set it to 40000.
However do note that when installing anything that lets you pick an install path, this requires you to remember to designate a drive other than C: drive for the install path. It's a simple thing to do, just edit the C: with the drive letter you want to install on in the install path. If you don't, your OS partition will become too full. Once you get in the habit of it, it becomes 2nd nature though.
Windows will also automatically make a small partition for critical system files, and though you can avoid it doing that, it's best for beginners to let it do that, because it helps avoid system file corruption that can be caused by things like letting an OS drive fill up too far, whereby non system files can interfere with system files and corrupt them.