Hi there,
I'm a Maryland local as well, and I *DO* love OC... but I don't recommend it.
Ocean City is the ultimate trashy-beach-town. That's what I LOVE about it... it's got character... but if I had to pay out-of-town money (we live close enough to day-trip) I would be P.O'd once I got there! It's safe enough for families, and plenty for families to do... just really expensive and you have the younger crowds running around in the same area... If you have a young son, be prepared to hear him talk FOREVER more about "That girl in the white bikini!" (nothing Rio, or anything, just some beautiful young people being young and beautiful while they still can... oh-- and some not-so-young, not-so-beautiful people with very poor judgement on what they can look "good" in...
) My husband LOVES the boardwalk area-- he enjoys the view... and I"m not talking about the water...
If you decide to come, consider looking for a house-for-rent in Fenwick Island, Delaware. The island is not an island, they filled in the channel... it' actually attached to OC now, out past the end of the bus line. It's very Norman Rockwell out there, and you're still super-close to OC... You can stay in Fenwick, walk to the buses, and ride the bus allllll the way down (long ride, about 160 blocks through traffic) to the boardwalk and the inlet and not pay any parking.
If you MUST stay in OC, it's going to be EXPENSIVE. Like $300/night for the HoJo's (beachfront) expensive...
OC is long and skinny(about 3-4 blocks wide in places), with one side facing the ocean (oceanfront) and the other side facing the bay (bayside). If you're going to stay there, you'll need to know that... bayside places should always be cheaper, but they are more likely to be condos/apts/timeshares. The highrise hotels are mostly oceanfront, with lowrise hotels and older (kinda skanky) proprietary hotels in the middle.
There's a candy store on EVERY corner, pretty much, and more mini-golf than you could play in a year... but there's also always a partygoing somewhere if you know where to look... so *sometimes* it's not so family-friendly. They really do try, though.
Bottom line, as much as I love OC and hope it never changes, if I was going to shell out the money for an overnight and take the fam, I'd be looking at Virginia Beach or Rehoboth.
Either way, prepare like you would for Disney ie-BYO sunscreen... EVERYTHING's expensive at the beach. ANY beach.
Good luck!