Yeah, building a PC is really just a matter of following directions. There are books and online guides that explain exactly how to do it, too. Picking which parts to buy is a lot more difficult because there are so many choices, though. Honestly, actually building it once you have the parts doesn't get a whole lot more complicated than "put the thing in the slot."
it also requires some planning ahead, and ofcourse some thinking, for example the case needs to be big enough to hold everything. if you're building a very basic computer it's not a problem, but if you've alot of hardware, the size of the case becomes more important.