Walekum salam
For English : Exploring the world of english by saddat ali shah
For islamiat : towards islamiat by Sm dogar
For Pak affairs : Sohail bhatti and ikram rabbani's buks are enough
For current affairs : Dawn newspaper,magazines,net, contemporary affairs by imtiaz shahid
Everday science : by Kashmiri
Essay : Its based on your knowledge so i would suggest you to have a research on a couple of issues such as woman right,democracy blah blah.
Start your preparation from english.
Improve your written skills and write whatever you read.
attempt precis ,essays and past papers.
Wish you all the best