Which book/cource is the best to go for? I am looking expert material. I managed adwords accounts, and read a lot here and there, I need a better material. Please recommend.
If you are google certified then read their provided material which is extremely relevant and explains the program throuroughly. If you are not google adwords certified I would recommend taking the class which is self taught using the provided material, and comes with certification upon completing the test. Hope that helps, I know its not a book like you were looking for, but in my opinion a book would just be referencing that material.
Google has a certification for its google adwords program. While you do not need to be certified to manage an account, it does make sure you understand how to achieve optimal results, gain a high quality score, and fully take advantage of the program. There is a fee for the course, but if the benefits of the course will definitely be considered an investment in yourself and your business. You can type in "Google Adwords Certification" into google and learn more about the course.
As a Google AdWords Professional, I can make some recommendations for you regarding AdWords. Please view my post of recommended reading materials: http://forums.digitalpoint.com/showthread.php?t=1985799#post15241396