@Asi01
Dear, I would again recommend the same book. There are other good books on this topic, but I mainly consulted Exploring the World of English. Precis Writing is not a hard nut to crack. One needs to remember necessary rules and apply these in the given passage. The suggested book contains guidelines and tips for Precis Writing along with some solved examples.
Here is also given some piece of advice:
http://www.cssforum.com.pk/css-compu...tml#post330439