Google maps is all right to get a rough idea, but its not detailed enough or accurate enough to really plan a route.

Bikely goes one better than Google and will give you an approximate idea of the elevation profile.

But paper maps are still your best bet, and there are a wide range of paper maps available. We just had a thread on this very topic.

See Maps thread: http://www.bikeforums.net/showthread.php/708263-Maps