Hi xubair,
Are we talking English language books? I'm also assuming we're talking non-fiction if you mention "learning".
Here's a search I quickly hacked together for you in Amazon. Can you use Amazon?
http://www.amazon.com/s/ref=sr_nr_n_...rnid=158280011
Unfortunately, I don't have any recommendations as such. I'm not really a non-fiction reader, but just in case a listing is helpful, I thought I'd drop that in for you.
Welcome to the site.
EDIT: Just checked a couple of titles in that list and some are less informative about the religion itself and more about some of the social history of the religion. I hope you can gloss over the more provocative titles and find something more suitable there.