Hey there. I did a lot of internet research on where to go for my first jump. Would of been so much more convenient if there was something still offered out of St. Mary's Airport, but alas, nothing. There are a couple of skydiving companies that operate out of Salisbury, and one in Bowie. Just do a search for "Skydiving in Maryland." And of course, there were quite a few out of Ocean City. I am more familiar with Virginia and the Orange Airport is very easy to get to, if a bit of a drive.
Wanna know something pretty funny? When I told my (soon to be divorced) husband that I was gonna jump, he turned white as a sheet, started sweating, and got extremely queezy - he is PETRIFIED of heights! And then he asked if his name was still on my insurance policy! LOL. Good luck to you!