I suppose a link to the Washington Post is sort of obligatory. Their web site is OK; I find it kind of hard to find my way around it, but they do have good content and I do read it sometimes (partly just because I feel I should, to be an informed citizen or something). A possibly better site (although more narrowly focused on DC politics) is DCWatch (in particular, their email list is sometimes very good, with contributions from Jeffrey Itell, at least one city council member, &c). Other publications I read: The Washington Blade, DC's gay paper. The online version is reasonably well done but doesn't (yet at least) contain all the content from the printed version.
The current (1999) restaurant to obsess over was Udupi Palace out in the suburbs.
The US Environmental Protection Agency has a page for DC. This has information such as a list of toxic waste releases in DC, volunteer groups working on the watersheds, and lots more information (I didn't try to look at it all). I was a member of the Washington Area Bicyclists Association. I shop at City Bikes for repairs and other bike merchandise. Their web site is great, with lots of information about their store and bicycling in general.
Co-housing: Takoma Village in Takoma, DC, Virginia.
Canaan Valley (Davis, WV).