Mon-Fri need coins for meters (9:30-3:30, rush hours no parking).
Street parking is very cheap. ~ $1/hr.
If no cars and walk on foot, be prepare for long walk (> 10 miles)
in hot Summer day (about 90F or 32C) to visit all important places.
There are some very closed hotels on Maine Av SW with water-front.
A few blocks to musuems. Seafood market with steamed crabs is nearby.
DC is famous of crime, whole east side is poor
and dirty (east of 1st St. or North Capital St.). Avoid hotels in
East of DC. South of DC (south of M street south) is also dangeous
and poor, avoid those place.
DC's north side (up to K Street or M street north) is good place to
stay. Safe walking distance to museums.
If you don't mind distance, Silver Spring is a good place to use
subway go to DC (easy direct line, $3). Holiday Inn, Hilton, Days Inn
, ... have hotels in Silver Spring. Prices are better than other
places. Many Mexicans are living there.
Whole North-west DC section is good place for living. Best DC
residential area is NW-DC. The area can be extended to 20 miles northwest to Rockville/Gaither*****urg. This large area is covered by subway systems and will good for your stay.
So place names are: Chavy Chase/Bethasda, Rockville, Gaither*****urg,
Silver Spring.
Good luck !
Please see DC Metro systems:
http://www.wmata.com/metrorail/systemmap.cfm
Rockville -> DC -> Silver Spring is same Red-Line.