Flight
The Metro can be easily accessed from DCA. Driving time from DCA will vary by time of day. If driving from DCA at/after about 2:30 on a workday, expect traffic and routes going through downtown DC.
Flight
Farthest from the wedding, but still a viable option. Accessible by public transit, but a car would be helpful.
Flight
Less likely to deal with traffic issues, since you don't have to go through DC or over the Potomac to get from BWI to the wedding. BWI is accessible by transit: the 201 bus goes to Shady Grove Metro, and the MARC and Amtrak trains pick up at the airport en route to DC's Union Station. From Union Station, you can transfer to Metro for the remainder of the journey.
Train
There is substantial rail service to DC from the northeast, and some from the south. DC's Union Station has an easy transfer to the Metro Red Line, which goes straight to Rockville. You will need additional transport (taxi or car) for the remainder of the journey.
Hotel
This link is supposed to give discounted hotel rooms associated with our wedding, even if we haven't set up a block.
House Or Rental
There are a variety of options available in the area. Note that when searching, we recommend searching with the ZIP code 20906 and checking the distance between the location and the wedding/reception; otherwise, you may end up in more distant parts of Silver Spring.