Hey firebug.... my wife and I are heading to Yellowstone next week too.... Leaving this Saturday and spending 4 nights in the Kalispell area and then 1 night in Helena and 2 nights in West Yellowstone (July 1 & 2) which is at the NW entrance.
We are going to do the Grande Loop and see all the sites on it (see #1 thru 10 (#7 not included on the map in the following website) ...
http://www.yellowstone.net/topten.htm
When will you be there?
Also... are you going to see the Lewis & Clarke Caverns (just west of Bozeman near Three Forks and Whitehall Mt)?
We're going there. Apparently they are quite impressive.