Hi Pete. You can pick up a great map of the area at any InfoTur office. I went to the one in Sucre. Route finding can be problematic in spots, but if you follow the Land Cruiser tour tracks, you should be in good shape.
The rough route is as follows:
Uyuni - Isla Incahuasi - Isla Pescado (camp for the night.)
Isla Pescado - Isla Incahuasi - follow tracks to the south exit off the Salar
South exit - San Juan
San Juan - Chinguana
Chinguana - 3 little lakes Go south from Chinguana not west!
3 little lakes - Laguna Colorado
Laguna Colorado - Hot springs
Hot Springs - Laguna Verde
Laguna Verde - San Pedro de Atacama
Check out this post for more info. http://advrider.com/forums/showthread.php?t=833958
This is epic South America riding and should not be missed.
Here is my RR post on the region: http://advrider.com/forums/showpost....65&postcount=2