Dear Azam
I m pleased to know that you are planning to join Civil Services.
In my first attempt I opted for Indo Pk History but this time (CSS 2005) I have not opted it. My objective is not just to pass but to score high marks so I opted for 6 subjects (all 100 marks). In first attempt I found that 100 marks subjects are easy to cover and score high marks. If you are interested to see my optionals then read my introduction. This is my personal experience that 100 marks subjects are easy. I am not suggesting that everyone should adopt this strategy.
In an earlier post I informed that for my second attempt I did my 50 % preparation from online sources (specifically
http://en.wikipedia.org). This is a wonderful resource and I it found extremely useful.
For Indo Pk History you must visit
www.storyofpakistan.com
Read other threads posted by me on this forum. You will find most of them to be quite informative and useful.