I am a new comer on this forum. I am looking for helpful e-book or PDF on Bitcoin, specially for new comers.

Here is one ebook that can give you the required information: http://it-ebooks.info/book/4480/

For newbies, the forum has a thread: https://bitcointalk.org/index.php?topic=7269.0

Also you can refer to the ebooks listed here:

https://bitcointalk.org/index.php?topic=86274.0

It's better to first check the forum thread and then refer to the ebooks.