This will answer more questions than anyone can possibly think to ask:
http://gpsinformation.net/
You don't have to spend a whole lot of money to get a decent GPS. As critter mentioned the Garmin Legend is a very popular model and does a lot. Magellan makes several models with the same features. I suggest getting one with built in highway maps. You can spend less than $100 for a basic GPS which works just as well telling directions and reception as one costing $500 but it won't have highway maps and other features. I carry an basic Garmin yellow Etrex for hunting as I got a great deal on it and don't have much money in it. I also have an older 12MAP which I use normally for traveling. If you got with a basic model first it won't be long before you'll be looking to trade up in features. For less than $50 more than a basic GPS you can get a GPS loaded with nice features, like the Legend or similiar. Save some money and spend a bit more with at least the highway maps and it will give you long service.
Whether you need/want one with an electronic compass, barometer, etc. is up to you and your requirements. All GPSs will tell you your direction but you need to be moving, altho a slow walk will handle that. Electronic compasses work just like regular compasses. The trade off is those models tend to eat batteries quicker. Personally, I prefer no electronic compass and just carry a regular compass as it also works as the backup to the GPS.
The 2 main companies are Garmin and Magellan. Which is better is the Ford v Chevy debate. Each has nice features. The models with the built in highway maps are not detailed maps. They'll show the major roads but won't have the minor secondary roads. If you want to download detailed maps then I recommend a GPS model that uses memory cards. That way you can DL maps to the cards and then pop in whichever card for the area you're traveling. Garmin only uses their own maps which can be DLed. They're pretty good maps tho. I believe Magellans are capable of DLing maps from other sources. Not positive on that so check that closer to confirm if that's a feature important to you.
Get a 12V power cord. GPSs eat batteries like a 5 yr old with a bag of M&Ms.
Know a couple of guys with the 600 and they like it. Haven't used one myself.
If you've never used a GPS before don't be intimidated at first. I've never seen an instruction book yet that was very good at explaining all the details. Just takes some playing with to get it down.
Another website you might want to try is
www.geocaching.com. It's an internet scavanger hunt where you use your GPS to find hidden caches all over the world. To date there's about 335,000 caches hidden around the world. Some are very easy. Some you need special equipment and training to find. Cache hunting will give you the chance to learn how to use your GPS well. There are other games that also use GPSs.
We never travel anywhere without a GPS. The more you use it the more uses you'll find to use it. As an example, today we're hiking an area along a river which is thought to have been settled 5000-8000 yrs ago. We'll use the GPSs to mark wherever we find areas that are either confirmed sites or where we might want to come back later to look closer. When I was in the USAF we used the GPSs to pin point aircraft parts locations after crashes. We'd mark the debris field on the GPSs, label the parts on the GPS, take the GPS back to the office and upload the data into the computer which would then give us a map of the debris field.
