To send your SAT's, you can either add which schools you would like your scores to be sent (typically done during the October, November, December tests) at the time you register for the exam. You can add/ change these schools for up to 9 days after your exam. You will get 9 scores sent for free by taking advantage of this option.
If you do not designate schools for your scores to be sent, you will have to pay for your scores to be sent to each school (except for CUNY's, put in "CUNY UAPC" and you will only pay one fee for scores to be sent to all six of your schools).
If you qualified for a fee waiver when you registered for the SAT exam, you will get 4 scores sent for free. Any additional scores sent you must pay for. ($12/ school).