I've been searching for a website that would give me latitude and longitude of a location if I only knew the place name; e.g., an intersection in a town. Bing Maps and Google Maps, as well as a couple of other websites like Lat-Long.com have been a big help, but just are not complete enough to be of consistent help. Lat-Long for example, has an extensive database but, if the place you are interested in isn't in that db, you're outta luck!
Just recently, I stumbled onto itouch maps! Find a place on the map, right click on it and the coordinates are returned in a box at the bottom left of the map. If you already know the coordinates of a place, enter those in the box at the bottom right of the map and that place is marked on the map for you. I use the satellite view and zoom in on a spot just to see if it is actually a church, cemetery, etc.
You may have to use a combination of the sites mentioned above, depending on what you already know about the places you are searching for. Sometimes, I have to look in on-line yellow pages for the address of a church that I know has an adjoining cemetery. If the church can't be found in lat-long, then I generally use Bing and enter the address which then places a marker on the map. I look on itouch for that exact place, left click on it, and the coordinates are returned. If the location is in the lat-long db, I use their map (all of the map sites use some form of Google maps) to zoom in and move around.
Once I have collected coordinates for a county of interest, I can upload them to my GPS.
Hope this helps!