Downtown Sailing Center and more.
There are tons of options in the area.
For instructional courses, and if near the Inner Harbor, the easiest option is probably the Downtown Sailing Center in Baltimore (DSC). They have various programs at different levels from dinghy sailing to J24's, racing, cruising boats etc. I know several people that started sailing/racing there and have always spoken highly of it.
If he wants to learn via the racing route, there are all kinds of options as crew as well. I believe DSC also races. And Near Baltimore are Rock Creek, and North Point sailing associations that race every Wednesday nights out beyond the Key Bridge on the Patapsco. GlenMar sailing Assoc. Middle River has a good sized fleet on wednesday nights as well. There is a lot of Racing on the Magothy River, a little further south as well. Then there is Annapolis, which has largest and likely most competitive fleets in the area with racing of some sort most days of the week. There are larger regattas all over the bay all season. There are many more.
SpinSheet magazine hosts a "Crew" party each spring that connects racing crew with captains. If he is interested in racing, it's a good place to start. Walking the docks with a small cooler of beer is always a good way to find a ride as well. Hope this helps.