I wonder what book is the best out there to prepare for CCNP Routing exam? Any suggestions please?
I have not read it yet, but I think one of the few current options (at least from Cisco Press) is the book by Wendell Odom.
The ROUTE Cert Guide by Wendell Odom is pretty good, it covers the topics required for the exam in good enough detail, and it will probably be the only resource needed. Of course you will need to gets some hands-on with real equipment or use an application like GNS3 in order to pass the exam. Lots of lab time is needed for the CCNP exams.
Here is a link to Cisco Press with all of the ROUTE materials: http://www.ciscopress.com/markets/detail.asp?st=44734
The ROUTE official exam certification guide(OECG) is a great book for the exam, but if you are not already somewhat familiar with those topics, you may benefit from taking a look at the foundation learning library as well.
I tend to gravitate towards Cisco Press materials as they are often top notch and with the newer ones especially they stay close to the exam blueprints.