Ficus elastica are part of the Fig family which is extensive and very versatile for use as bonsai. There is a good article on Ma-Ke Bonsai on how to look after a Ficus elastica.Plus check out this you tube video on Ficus elastica.
Great books on Figs include:
• Ficus The Exotic Bonsai by Jerry Meislik
• Ficus Tree & Ficus Bonsai Tree. The Complete Guide to growing, pruning and caring for Ficus by Bernard Brook