The USGS has a comprehensive series of resources available listed
in their web catalog.
The materials are available in paper, html, or PDF format.
One of the most exciting and valuable resources is a full-size poster of Gerardus Mercator. The reverse side of the poster is a comprehensive list of map projections and their respective qualities.
See the information printed on the poster here.
A free copy can be obtained by calling 888-ASK-USGS or emailing ask@usgs.gov and asking for the folded Map Projections poster # 16573.
For a large quantity of the free Mercator posters contact:
USGS Information Services
(Map and Book Sales)
Box 25286
Denver Federal Center
Denver, CO 80225
Telephone: (303) 202-4700 or 1-888-ASK-USGS (1-888-275-8747 Option 1)
Fax: (303) 202-4693
Email: infoservices@usgs.gov
The posters from Denver will still be free, but a $5 handling charge will apply