Yahoo maps recently got upgraded with a new interface. One of the features allows you to place the cross hairs on a road and right click -> "Drive to here," and it adds the destination to your itinerary. You can create a route simply by plotting some of its key points. It's not quite as good as mapping software, but it'll pass.
http://maps.yahoo.com/index.php (make sure to click broadband map in the top right if the old interface comes up)