Answer
First you need to buy a gps receiver. you can either buy a full-featured gps - such as a garmin gpsmap 60 series, or a simply unit/antenna that is nothing but a small receiver and either usb cable or bluetooth wireless connection to the laptop.if you buy something new (real receiver or small receiver for laptop navigating) it will come with software. garmin units use a program called nroute. nroute has complete turn-by-turn, with voice, directions - it is great. i use it with a real gps and a usb cable connecting them.
