Hi Bhanwar,
Am I correct to understand you are mostly working with Active Directory Domain Controllers?
If you want to learn more about Active Directory courses you should the out the preparation tab of the
70-640 Windows Server 2008 Active Directory, Configuring exam.
I would also recommend the
MCTS Self-Paced Training Kit (Exam 70-640): Configuring Windows Server® 2008 Active Directory® (2nd Edition). Be sure to get the 2nd edition which will cover the new features in Windows Server 2008
R2. I have used the first edition a few years ago to freshen up and to prepare for upgrade exams from MCSE 2003 to MCTS 2008. I just glanced at the table of contents again, and concluded that every chapter is useful for almost anyone who works
as an administrator, so it's a great value to read this book. Even if aren't planning to take the exam.
The next version Windows Server 2012 hasn't been released yet but you can learn about what's new in this free ebook:
Introducing Windows Server 2012.
