I have a garmin 152 GPS ... Someone owed me money I got this ...how do they work????? and so on any help would be get I just want to see if it works and then I will sell it....

you can download the entire manual and this web site
www.garmin.com
The GPS 152 is a 12 parallel channel GPS receiver loaded with a database of American cities and nautical navigation aids such as lights, buoys, sound signals, day beacons and tide data. Built-in memory of one megabyte makes the GPS 152 compatible with Garmin's MapSource® Points of Interest CD. With this CD and the GPS 152, you add additional marine navaid detail to your unit. (Other point of interest features from the POI CD-ROM will not be available for use with the GPS 152.)