Will taking AP World History help me with the subject test for world history?

Hello,

I am currently enrolled into AP World History and I am considering to take the SAT subject test. When should I take the subject test? I will be taking the AP exam May 11 (my other regular school exams, finals, will be in late May up to the 31) and the subject test is offered June 3 and August 26 (my school starts the 21). So I’m not really sure of when to take it. Also, this will be my first subject test so could anyone recommend how I should prepare? Which prep books are the best?

Any feedback would be very much appreciated…