YOu don't even need a book, just go to some of the maker's sites, they have fairly good descriptions. Take mine for example.

I have a wireless router that has four ports for wired connections on it. It plugs into the DSL modem that use to plug into the PC.

Now the router handles all the DSL stuff for any PC (or MAC) I wanted to add. The desktop is plugged directly to one of the four ports, and my wife's work laptop has a usb wireless connection so she can work anywhere in the place when she works from home and get full speed DSL.

Choose USB because the laptop didn't have an available pcmncia slot, and if you take the cards in and out every day, eventually (not that far in the future) will need to send it for repairs.

In answer to the second question, yes, if you have a wireless connection or it's built in, all you have to do is walk around, it will eventually pick up a network and turn green.