I am student of CA and also interested in government job as CA is not progressing well. I opted Accounting and Audit as my subject in CSS as I already had some knlowledge of exposure of Accounting. I found that if you are prepared technically for the Accounts paper, you are likely to get high marks. I am sharing you an accountancy website from where me and my seniors take help in CA matters.

Somebody was asking about Cost Accounting Book in this topic. I remember, when I was intending to prepare Cost Accounting, I was very much concerned about its theory. I was very good in numerical portion and was able to secure good marks in it. But theory was the only portion that used to disturb me as I was not very good in it.