Minimum of 2 books. Waggoner (general info and guidebook) and Ports and Passes (tides and currents for Washington, all of BC).
Depending on where you plan on cruising, and if you want to go to out of the way places to anchor, then the various Douglas (author) cruising guides (organized by area) often give details that Waggoner does not. If you have a computer or tablet on board, don't forget to download the Government documents called "Sailing Directions" in BC (free). If I remember correctly they are called "Coast Pilot" in Washington.
There should be several places to obtain charts in the Seattle area. That should give you a good start on your "guidebook" library.