Thank you for the post, Becky.
Others will likely offer additional advice, but I wanted to note that I can highly recommend Garmin products (full disclosure: Justin and I are shareholders, though not "big time" ones, by any means). We own a variety of Garmin GPS units, and have for years. My favorite right now is their Forerunner unit, which is not really a geocaching unit (though any GPS can be used for geocaching); instead, it's aimed at runners, walkers and cyclists since it can be worn on the wrist or mounted on handlebars.)
My current geocaching unit is Garmin's
GPSMap 76S -- it's water resistant, has topographic mapping capability (if you purchase Garmin's MapSource TOPO CD's), has a large, readable display and a built-in electronic compass. I'll actually be putting mine up on eBay soon to help fund some other geek-gear purchases (a new computer, for one; and a new portable GPS navigator for our vehicles). It'll be a couple more weeks before I get around to posting mine on eBay, but it's in the original box with all the original materials (manuals, etc.)
I have nothing against other GPS makers, by the way, I've just had no reason to switch from Garmin. We have their mapping products and are comfortable with the user interface on most of their models (the Forerunner took a little bit more time to get used to, actually), so it's been a logical choice every time we're in the market for a new unit.
Definitely research what's available and pick the right unit for your price range and expected use. We've found that no single GPS is perfect for every use -- we use a different GPS for geocaching and hiking than we do for biking, and different units still for more specialized things like in-vehicle navigation or flying (Justin's a licensed general aviation pilot, and a GPS is an added layer of safety and redundancy to the aircraft's built-in navigation and wayfinding systems.)
If we can provide more details, or point you toward additional geocaching websites (you've found my favorite, already), let us know!