MapChick Map & Travel Guide is the only map you will ever need for Isla Mujeres! Take advantage of Laura (MapChick) and Perry's 20 plus years of expierence traveling the Yucatan Peninsula.
The current addition is a four map set:
Map 1 - Getting to know downtown and the island
Map 2 - Restaurants
Map 3 - Hotels, rentals, beach clubs and tours
Map 4 - Golf cart tour
Be sure to order at least 3 weeks before you leave for Isla Mujeres, you'll want plenty of time to browse your map!
It's loads of fun to wander the streets of Isla Mujeres with Google Maps Street View, I do it myself before I travel. Just remember, that the current version of street view is from April 2014. Have fun!