There are three computers in our house. Martin has a laptop, so do I and Wille has a stationary one. Martin's and mine are connected to Wille's and with the three of them and all the network stuff there are a zillion manuals, codes, passwords etc to keep it all handy in one spot I compiled a binder.
It works really well and we know this because rarely a week goes by that we don't have to consult it for some reason or other.
What I did in order to find everything easily was to add plastic sleeves for each piece of equipment. In the sleeve I inserted a piece of cardboard (red backing was just what I happened to have a bunch of) to make the sleeve sturdier.
Then I insert all the manuals and discs that belong together in one sleeve. I make sure to get rid of any manuals that aren't in either Swedish or English and for those fat multi-language ones I simply tear out the section I'm interested in so I don't have to flip through Dutch, Norwegian and Finnish in order to find the info I'm looking for. To make sure it doesn't come apart I staple the spine. Not the most attractive solution but it works.
I added handwritten labels (these were from Martha by Mail back in the days) in the top right hand corner on each sleeve. This one contains the instructions for our mobile internet stick.
And there it is, organized and ready for the next time I have a fit over some internet connection, e-mail application or something else IT related.