The Group Policy book from the Windows Server Resource Kit has recently been made available through MS Press as a seperate book. Although the resource kit has loads of great information, many people often only want one book. This is one of the best books from the resource kit (well, actually, they're all good). It was co-written by industry-expert Darren Mar-Elia, Derek Melber, William Stanek, and the Group Policy Development team. I've included the description below:
Get the in-depth information you need to use Group Policy to administer your enterprise system—direct from industry experts and the Microsoft Group Policy team. With Group Policy and Active Directory® directory service, administrators can take advantage of policy-based management to streamline the administration of users and computers throughout the enterprise—from servers running Windows Server 2003 or Windows 2000 Server to workstations running Windows XP Professional or Windows 2000 Professional. This essential resource explains how to simplify and automate administrative tasks, including policy enforcement, system updates, and software installations, as well as how to centralize the management of network resources. The CD provides essential utilities, custom ADMs, GPO spreadsheets, and more. It’s everything you need to help increase your efficiency while bolstering user productivity, security services, and system reliability.
For more information, check out the book’s web page.