What should I do to prepare for Navy boot camp and "A" school?

I'm going into the Navy as an EN-1 HM. I leave for basic at the end of July. I've been reading my start guide frequently, memorizing as much as I can. What should I prepare for physically for those who have been there already? I'm 5"8 and 140 lbs. I play hockey but I don't think that counts for much. Also, what should I know about and prepare myself for in corpsman A school?