bro I studied books like caravan ,dogar, jahangir and past paper of ppsc or fpsc and I recommend you to study the five year past paper of ppsc or fpsc which will help you alot
internet is a best friend in modern era you can take a lot help from it
one thing more plz clear your's concept like pakstidy islamic study world history war ,geography ,map reading
if you study mcqs , clear the concept around it
for example if you study when world war 1 started
you should try take help from internet and study ins and outs of world war 1 when started, why started , who president of usa etc
download good dictionary in your's mobile because most important event also present in dictionary which give you help alot and save your's time