see if I can help. A lot depends on how you want to use it. If just for road travel there are many that will do it. If you want to do more than road travel like Geocaching, or hiking in the woods or figuring acreage, then there are different types of GPS to do that. Garmin makes a very good GPS as does Magellan and many others. My choice is Garmin when it comes to hand helds for geocaching as the company backs its product up very well, offers a lot of different software for them. Most upper end hand held GPS come with a base map on them for land and roads. The basemap has the entire USA on it but usually the main roads but not the rest of the little roads. The same in Cities, unless you get a good software program for roads, the citys roads are not that great. If roads are what you are interested in and I think that is your main interest. For easy of operation, I would suggest a handheld automotive unit. There are many of those to pick from, but from what you said, you don't want all the bells and whistles, just the roads and simple use. Lots of people making those now that have a very good base map with very good road coverage for the back roads. These can be had for from $100 dollars to $600 dollars or more. Right now there are a lot of them on sale new for entry level but very nice, just for roads for $120 dollars at Staples, Wal-marts and other electronic stores.
the Garmins like Royal and I have are high end units but they are made to do more than roads and have a lot of others things they will do. The learning curve on them is much steeper and how I've picked up most of mine used as others got them and just wanted a road GPS or Automotice GPS and nothing else.... Do go and put your hands on some....See the size, the ease of use, etc. The make some with batteries that are rechargable and some that just plug in the lighter socket. I personally prefer the ones that will use Double AA batteries as they are easy to get, no charging needed and I can have a pack of them on me for anywhere. Its not much use to you if the battery dies and no spares or it needs to be recharged only and you can't out in the boonies where you like to go. If you have a lighter socket on your bike your golden even there. check out this link to
http://www.staples.com/office/supplies/c2_Technology-GPS-Accessories_10106_Products_10912_12292_Business_Supplies_1_10051_Technology
Here is a link to staples to start with...They have a lot of them and one for $119 bucks that might be all you need. Again, there you can hold and feel them, and have them show you what it does. Have them bring it up or better you bring it up for your area and see if the map is accurate enough for your area and shows paved and dirt roads. The sound, you can normaly turn off on all of them.
Even refurbished ones are fine.... I have a couple of them and they have never acted up. EBAY has them also. Wal-marts has them, as does Radio Shack. They all work pretty much the same with pretty close to the same accuracy.
Here is another link and store I use and they carry them all.... http://www.thegpsstore.com/Automotive-GPS-C1.aspx Good place to read for info.....
start there and if you have more questions, feel free to ask...........Geo