www.mapmyride.com lets you see the elevation profile and estimated amount of climbing. I also use the MapSource maps that I got for my Garmin GPS. Plot the route using the street maps and then look at the profile using the topo maps - it shows the profile but doesn't give a cumulative gain figure. DeLorme's Topo map programs are another option - they also give a profile and cumulative gain estimates (but I've found the latter to err on the high side).