There is a series of four books by Anne and Laurence Yeadon - Jones that make excellent cruising guides for the San Juans and BC coast. There is an older series by Bill Wolferstan as well. Both offer great info on the area. I do no know if the Wolferstan series has been updated my are dated 1987. Good aerial shots of anchorages to give you the "lay of the land" so to speak.
Recomend either set to anyone thinking of spending some time in our part of the world