If you are going to be in more than a few Mexican states it is more economical to get a road atlas. The maps are easy to use and provide the latest information available to the traveler.

Good mapping for the entire country of Mexico in a spiral bound format comes from Guia Roji in their Por las Carreteras de Mexico road atlas. It shows multiple types of roads, toll road info, parks and natural areas, plus a wealth of information on traveling in Mexico. Pre-order the 2011 version now.