HOKAPOO712 :
NEED HELP with new computer build
It's really a lot like LEGO bricks, but way more expensive. Find the cables that fit into certain sockets, repeat. Some cables are labelled too. Congratulations, you now (hopefully) have a working PC!
As for installing an OS you just put in the disk, follow the directions, pick some settings and leave it alone.
Once that finishes, install drivers for your GPU, motherboard, etc.
Once you do all that, a bit of stress testing with Prime95 or Furmark wouldn't hurt.
Just make sure you don't drop the thing and you should be fine. Oh yeah,
ground yourself often while building.
EDIT: Well, that's a completely different question....