If you are buying a new computer, it is best to select one with a wireless component that is designed for free software like Linux. A card designed for free software gives you improved support. Free software compatible devices also work out of the box.
To determine what wireless card/chipset you have, first determine whether it is a separate device plugged into the computer or not. If it is a separate USB device, open up a terminal and type the following:
and look for words like "wireless" to find your card type.For chips that are not USB but included in the computer, type:
$ lspci -v
List of Linux Compatible network adapters available here