This Guidebook provides an overview of the mission and functions of Transportation Management Centers, Emergency Operations Centers, and Fusion Centers. The Guidebook is focused on the types of information these centers produce and manage and how the sharing of such information among the centers can be beneficial to both the day-to-day and emergency operations of all the centers. There are some challenges to the ability to share information and these challenges and some options for addressing them are addressed in the Guidebook. The Guidebook also provides some lessons learned and best practices identified from a literature search and interviews/site visits with center operators.