Originally Posted by Ali Mubashir

1.Encyclopedia of general knowledge by jahangir success series.
2.Caravan general knowledge by chodhry najib.
along with these books kindly cover some English Grammar as well, either from Wren and Martin Grammar book or from exploring the world of English by Sadat Ali Shah.
In above mentioned general knowledge books u will also find some basic arithmetic and I.Q portions must cover these both areas as well.
for current affairs and vocabulary go through the daily DAWN.
for further knowledge internet Wikipedia is also a best tool.

by doing all above practices one can easily get the rid of ASSISTANT DIRECTOR test of intelligence bureau.