Hosting a large database of roadside hotels and motels, when entering this site you have to take into account that you need to have your map next to you in order to plan your trip, as you will only get addresses and not driving directions or small drawings showing where to turn. However, the site includes information for all the states in continental US, several countries in Europe, largest cities in Mexico and a couple of Asian countries.
When taking the highway, its probably best advised to take this URL plus other supporting material, as this site will allow to have some idea on background and history, but not much practical information. Also, the site gathers some comment by other users, than can be orienting as of the pros and cons of lodging in one hotel or the other, and other useful information, such as if kids are welcome, if you can carry your pet into the hotel and the like. And of course, the usual benefit of having the advice of someone who has already been there and can tell you if visiting certain spot is worth a three-hour detour. 
