On this page there are two maps:  on each, you can zoom in and out and you can select which background layer you want (Open maps, google satellite etc)
—> To get your chosen track to show up in the second detail map, you can simply click the appropriate link in the list of links to the right.

A map (top) showing all the tracks
– on this you can click on track names and see which they are when they are highlighted on the map.
A map (below) of detailed information about a chosen track.
– Play with this one – you will see that you can view (very rough and unreliable) grades and the gps elevations.  As you move your mouse over the profile, you will see your position on the track above.