I want to learn Networking & its Fundamentals. Please suggest me a good ebook to learn networking.
It depends upon what type of Network you want to create and what aspect you want to learn about Networking?
Cisco Press do some nice simplified books on Networking I believe most are also available in e-book like formats.
For example: http://www.ciscopress.com/bookstore/browse.asp?st=60114 (those few are for beginners).
Obviously I have read the more complex Cisco books, i.e. the CCNA material but that is beyond the scope of what you are wanting if you are just beginning.
So I'd suggest looking at the Cisco "First-Step" books.