Get yourself on to member map (on the forum, profile, calendar etc. ...er toolbar above) and then at the bottom of the map it says click here to edit or put yourself on the map (or something like that), click on that and it will take you to Modify Profile, where you will see the map again, find where you live (CAUTION don't put the arrow/marker thing right where you live, but near it, no need to advertise where your bike is!) and then click on the map, in theory it should put the marker there, then (I think) you just click on save profile and your done. Hope that helps
And yes your right the member map is too crowded, much better to put the area or city where you live, in the box on the left.