I was 11...although I do remember rubbing myself and getting sticky on the climbing robes when I was 8 or 9.
I was in 6th grade. I remember that I stole a playboy from my friends dad and jacked it in the bathroom.
I honestly can't be sure. I THINK it was 7th grade, but maybe 6th. So I was... most likely 12. Probably not as young as 11. I do have a friend, however, who in one of our more personal conversations, explained to me how she started when she was 4. Now THERE's an accomplishment. Orgasms from age 4 and up!