An info road is a very valid tool to browse Cuba in car. In your country or direcly in Cuba you will not have trouble to purchase one.
One of the best road guide in Cuba is AUTOMAPA NACIONAL, by Havana Geo Editions.
In this guide, a part of the detailed map of Cuba you also will find a very detailed info road of Havana Province.
You can buy the AUTOMAPA NACIONAL in all touristic shops or authorized car renting offices.
The speed limits in Cuba are : on the highway, 130 Km/h, on the national roads the limit is 100Km/h. And finally, in all urban centers the limit is 50Km/h.