I would recommend the following books for the preparation of compulsory subjects:

ENGLISH
New College Composition by dave, Verma, Aggarwala
Brush up your English by S.T. Imam
Precis Writing by R. Dhillon

ESSAY
Dawn Articles (Editiorial & Opinion)
202 College Essays by Martin

GENERAL SCIENCE AND ABILITY
General Science and Ability by Dr. Muhammad Akram Kashmiri

ISLAMIAT
Competitive Islamic Studies by Dr. Shazia Ramzan
Rehbar-e-Islamiat by Muhammad Asif Malik
Maruzi Islamiat (MCQs) by Asif Malik
Islamic History by M.Ali
Islam Its Meaning and Message by Khurshid Ahmed
Islam at a Glance by Sadruddin Islahi

PAKISTAN AFFAIRS
Pakistan Affairs by Syed Mohsin Raza
struggle for pakistan by ishtiaq hussain qureshi.
Pakistan Affairs by Imtiaz Shahid
MCQs by Imtiaz shahid

CURRENT AFFAIRS
Read Dawn Newspaper daily for this part
Buy a good Science book such as General Science and Ability by Kashmiri
get your hands on a good Who is Who and What is What book. Try the one by A.H. Publishers, it has some contributions from Foreign Authors as well.