Well, its really not much more complex than I said.
You get yourself an amplifier, and plug your speakers and computer into that.
You get at least 2 front speakers and 2 rear, but a subwoofer or something as well will add to it.
This system will cost about the same as a good pc hi-fi system, however the home hi-fi system will sounds much better IMHO.
You can also plug lots of other things into the amp as well, like your DVD player, CD Player, cable TV, etc, and use these same speakers for this. You can make your PC just a channel, as such, on your system. You can even plug your TV into the PC as well, so that the PC is a channel on the TV and also a sound channel on the amp.
Believe me, this kind of system kicks the crap out of PC hi-fi. And it will be a lot more upgradable. You can add better speakers, or a seperate CD or DVD player, or something, as well later on. Its an open system, much like a PC.
Please believe me when I say that a good home hi-fi system will sound a lot better than the PC speakers you will get. And as I've said, its a lot more versitile.
A few years ago, I was all set to spend a pretty penny on a PC hi-fi system. Then a good friend saved me, and steered me towards a reputable hi-fi store. I promise you, it was first class advice and I really do, in all honesty, urge you to do the same.