Pros: small, lightweight, inexpensive, and easy to use
Cons: accuracy, compass, limited features
The Garmin eTrex Handheld GPS Receiver is a great GPS for anyone who has little to no experience with GPS units and wants to become familiar with one. The eTrex is small (2 x 4.4 x 1.2 in) and weighs just over 5 oz. with the batteries. It uses 2 AA batteries, but they last for about 20 hours. It won't float in water, but it is fairly waterproof.
I got my GPS as a Christmas present several years ago and was excited because it was my first one. I found it to be easy to turn on and also easy to learn how to scroll through pages, change the display, darken and lighten the backlight, and change back and forth between UTM's (universal transverse mercator coordinate system) to lat and long (latitudes and longitudes).
I've used it to find geocaches by typing in the lat/long and selecting the "go to" feature. An arrow will show up on the compass and point you in the right direction (as long as you're moving). It will also give you the distance (as the crow flies) to the lat/long you entered from your current location. You can change the display from the compass to a map view that shows a little person walking and a trail behind that person showing where you've been. You can then change the display to the satellite page that shows the number of satellites and the strength of their signals. There's a little box that shows accuracy in feet that can be changed to show an odometer, trip mileage or time, speed, sunrise/sunset, or local time and lat/long. You can also reset a trip at any time and hold and change options with one hand.
The eTrex is so simple that my wife's middle school students were able to learn how to use it to find a geocache in about 15 minutes as they were walking towards it.
It doesn't have a built in memory or preloaded maps and it doesn't accept memory cards so this isn't a GPS for users needing more intense capabilities. It can hold 500 waypoints (locations you save on the GPS and can access again) and 20 routes.
It also includes sunset/sunrise and moonset/moonrise information, local time and date, but no altimeter or other fancy features of more expensive GPS receivers like tide tables, a camera, or turn by turn directions for roads.
One of the cons of this GPS receiver is that the compass will not point in the right direction unless the GPS is moving. My wife tried to use it out in the field while doing some environmental research and had a hard time finding exact locations because of this. The other con is that it's not extremely accurate. It doesn't have a highly sensitive receiver so it's accuracy can be a bad as 30 feet if you don't have good satellite communication. 30 feet can be frustrating if you're looking for a small geocache or a very specific lat/long location.
For the beginner, this is an inexpensive and great start to the world of GPS. Unfortunately, Garmin has discontinued this early version, but you can pick up a used one online for fairly cheap (around $50) which is quite a steal.