On Design*Sponge is a DC Design Guide. I love that people hee and all over are seeking out unique furniture, handmade decor, craft pieces, DIY project opportunites, and the like... I swim around in the (not mutually exclusive) ponds of 'fine arts' and 'craft' and 'design', and sometimes I wish that 'fine arts' might be a bit more accessible, locally, in the commercially robust way that craft and decor have become. (As an educator, I want art to be accesible in general, too -- a whole 'nother pond o' fish.) Ayway, I do love how "ambassadors" like Kristina Bilonick of Pleasant Plains Workshop promote local art and craft, how Chandi Kelley of Project Dispatch makes art collecting affordable and fun, while helping working artists support their creative endeavors.
For what is is worth, I added the comment below to the D*S DC Design Guide -- I know it isn't an 'art guide', but there is such an intersection, and the more the merrier in generating new and creative ideas and making DC a place where original visions thrive!!
***Great guide, and I'm glad to see DCAC included and Crafty Bastards mentioned, above! I'm a DC artist and would love for more folks to discover our creative scene. Here are some other great spots:
Check out Pleasant Plains Workshop, an artist-run studio/gallery space/store near Howard University. Cool silkscreened items and other crafts and art by local artists: http://pleasantplainsworkshop.blogspot.com/
Industry Gallery features international design: http://industrygallerydc.com/Site/Home.html
52 O Street Studios is a decades-old studio building with dozens of artists and crafters, from painters to furniture makers to filmmakers and more. There are occasional open houses: http://www.52ostreetstudios.org/
Check out Pyramid Atlantic in Silver Spring! In addition to their awesome gallery and papermaking and printmaking studios for resident artists, they offer classes in letter press, papermaking, and more. Upstairs is the Washington Printmakers Gallery, with some beautiful (and relatively affordable) work. http://www.pyramidatlanticartcenter.org/
The annual Capitol Hill House Tour is great and occasionally also includes a peak into work spaces, like the one I share with decorative painters, custom furniture makers, photographers, and florists! http://www.chrs.org/Pages/1_Projects_11Tour/2011-chrs-tour-brochure.pdf
Flashpoint, Transformer, Civilian, Hamiltonian, Project 4, Harmon Art Labs, The Fridge (near Eastern Market), Heiner Contemproary (in Georgetown) and Conner Contemporary are some galleries that feature work by emerging and mid-career artists from DC and elsewhere, often inculding work at all sorts of price points for those interested in buying original art. There are also some artist-curated 'house galleries' and alternative spaces like Bloombars, and the Washington Project for the Arts presents the work of area artists. For an extensive list of art goings, the Pinkline Project is a great resource, http://pinklineproject.com/.