What is the context? Do you mean disaster recovery for businesses, individuals, or countries? If you're referring to disaster recovery in the sense of mitigating, preparing for, managing, and recovering from things like natural disasters (e.g. tsunami, earthquakes), the Wikipedia page [1] on emergency management is probably a good start. If you have access to something like the ISI Web of Knowledge (via a university), some good journals include The International Journal of Emergency Management and Disasters. Look for review articles to start off with, as they're most likely to give you an overview of a particular aspect of the disaster field.

[1] http://en.wikipedia.org/wiki/Emergency_management