How do I use a wireless N router?

When I’ve looked at wireless N routers, it says you need attatchments for the computers that are going to use it for connectivity.

Do I have to have extra junk? I have a macbook (the second to most recent one), and the desktop computer that would be hooked up to it via ethernet is a windows XP unit.

right now i have a netgear wireless g rangemax, and it doesn’t cut it to get constant signal in rooms on the other side of my two story house. I want to get an N router, but I don’t know if my laptop will even work with it, given that it has no pci slots or anything.

thanks.