UPSC recently announced on their official website that soon they will release some copies of model question Paper for CSAT.
Thinking on general terms, we can come up with a paper which would pretty much be like a CSAT paper.
In my opinion, to begin with, those who are preparing for the CSAT 2011 exams should start with strengthening their fundamentals, especially Mathematics. Mathematics is the foundation and rest all depends on how good you are in it.
Once you have done some ground work and are confident in solving mathematical problems, then you should start working out problems from R S Aggarwal.
That should be the strategy to begin with. I’ll soon update with the CSAT 2011 Model Paper. Till then, you can do the above.