locating birth records
Hi, I want to find birth records (birth certificates if at all possible!) for 2 different people born in 1930 (both of them are deceased). For one of them, I know his name, date of birth, and parents' names, but he could've been born in North Carolina or Virginia, USA. For the other one, I know his name and date of birth, but I don't know his parents' names, and he also could've been born in North Carolina or Virginia. Both of these people lived right on the border of those two states.
I'm obviously displaying my beginner ignorance :) (and I have tried to do an online search to figure this out), but what places should I contact for information of this sort, please? I'm not local to these areas.
(For that matter, I'd like to get the same for my own grandparents, born in 1924/1932 and deceased in 1986/2003.)