The following should prove useful for paper 1
a. "Physical Geography"by Stahler , recommended by FPSC for Geography
b. Goh chen long certificate of physical geography by oxford press
c. and Das Gupta on principles of Physical Geography
The fist two are sometimes hard to find but the third one is easily available in the market
These following should help in paper 2 of geography
comprehensive geography" by "M Jahangir Sanpal" also marketed by the exam cram series of Jehangir books
Geography of Pakistan by Fazl-e-Karim
I studied all three books for paper 1, though the main emphasis was on the certificate of Geography with the other two books being used as referencing and detailed versions of topics.
For paper 2 visit wikipedia site for specified topics that you cant find updated info on. to get the hang of the general concept, read the book by Fazal Karim and then go for the Sanpal one, you should be able to get the hang of it.
There is also another book for the maps and the classification systems thereof, but i forget its name right now. Do consult that any good book on maps as MCQs in paper 1 tend to come from there as well
Also go through the past 5 years papers of Geography of CSS exams.
As to whether you want to go for it or for any other subject, its a gut feeling combined with intuition. I had studied it in high school, and felt i could score decent marks in it ( which I did
)
If you don't have a background in it, then give it more time in preparation.
@ PArtixlean
P.S. Diagrams are a must. Majority of your answer should have one or more whether in paper 1 or 2. They are easy to remember and draw in a short time.
No diagrams = Low score
Tc
Regards
Vsvsr