I did a small tour of some of the local used bookstores here in the NW part of the District. After coming from Vancouver where there are a ton of good stores I was a little surprised at the dearth of places to find novels here. It could be the "Barnes & Noble/Amazon" phenomena.
The shop closest to my house is called Idle Time Books(2467 18th St. NW 202-232-4774). It is the best bookstore that I have found so far but I have also been able to spend quite a few hours poking around there. The store is 2 full floors and has a nice open layout. For the most part, the shelves are all single layer and fairly alphabetized. They pile overstock on the floor in front of each section but they're in boxes and easy to move. I've managed to find a couple of good treasures both in hardcover and paperback. Definitely worth checking out.
The second major bookstore in the area is Second Story Books (2000 P St. NW 202-659-8884) located in in the Dupont Circle area. They also have two other locations in Rockville and Bethesda. This looks to be a well established store (you can often tell by the scent and dust) that has a good reputation. Their primary focus is on hardcovers although there was a small crime and sci-fi section. As it was a sunny day they were having an improptu sidewalk sale where all hardcovers were $4 - some good selection too. This store will certainly be on my list for checking back and spending a little time - especially the history section.
The final bookstore that I went to today I just happened across while I was walking around the neighbourhood. It, too, is near Dupont and is called Kultura Books (1706 Connecticut Ave. NW 202-462-5015). Unfortunately, there's not a lot that I can recommend on the positive side for this shop. It suffers from many of the factors that make you not want to browse. The shelves go floor to ceiling and the books are shelved three and sometimes 4 deep sometimes. When I am browsing through a bookstore I hate having to pull out and put back handfulls of paperbacks. And there is just not much space in there which makes it hard to get around. They had a tiny sci-fi section and a not much larger crime one. One final complaint: the proprietress was unfriendly and smoked cigarettes incessantly. Don't get me wrong - its pretty cool to hang out and chat with the classic bookseller who smokes the occasional pipe but you have to be nice in a used bookstore and ciggies stink up the books. On the positive side, there was a pretty good film section. Also, I picked up a sweet Michael Innes novel.
There is a small cluster of booksellers in Capitol Hill that I will try to get to soon.