Listmania!
Cold Water Aquaria
By an Amazon.com customer
The New Marine Aquarium: Step-By-Step Setup & Stocking GuideThe New Marine Aquarium: Step-By-Step Setup & Stocking Guide by Michael S. Paletta
Buy new: $13.57 / Used from: $8.97
Considered one of the best books on modern aquaria.
The Rockfishes of the Northeast PacificThe Rockfishes of the Northeast Pacific by Milton S. Love
Buy new: $19.72 / Used from: $9.59
A beautiful book with great photos and a good level of detail about a large variety of rockfish.
Seashore Life of the Northern Pacific Coast: An Illustrated Guide to Northern California, Oregon, Washington, and British ColumbiaSeashore Life of the Northern Pacific Coast: An Illustrated Guide to Northern California, Oregon, Washington, and British Columbia by Eugene N. Kozloff
Buy new: $19.77 / Used from: $39.32
If you want to get serious about the species you keep, here's their life histories.
Coastal Fishes of the Pacific NorthwestCoastal Fishes of the Pacific Northwest by Andy Lamb
Buy new: $18.21 / Used from: $2.99
The best PNW fish book with loads of natural history infor about different species.
The Intertidal Wilderness: A Photographic Journey through Pacific Coast Tidepools, Revised EditionThe Intertidal Wilderness: A Photographic Journey through Pacific Coast Tidepools, Revised Edition by Anne Wertheim Rosenfeld
Buy new: $21.09 / Used from: $6.60
Very beautiful book with a focus on the PNW
Guide to Marine Invertebrates: Alaska to Baja CaliforniaGuide to Marine Invertebrates: Alaska to Baja California by Daniel Gotshall
Buy used from: $18.64
Pretty comprehensive and very nice looking book on PNW inverts with an emphasis on identification and a brief life history
Pacific Coast Crabs and ShrimpsPacific Coast Crabs and Shrimps by Gregory C. Jensen
Buy new: $21.51 / Used from: $17.99
same publisher, great book on crabs & shrimp, very colorful
Pacific Coast Nudibranchs: A Guide to the Opisthobranchs Alaska to Baja CaliforniaPacific Coast Nudibranchs: A Guide to the Opisthobranchs Alaska to Baja California by David W. Behrens
Buy used from: $25.94
Sea Challengers series again. Best coverage of nudibranch I've ever seen!
Whelks to Whales: Coastal Marine Life of the Pacific NorthwestWhelks to Whales: Coastal Marine Life of the Pacific Northwest
Buy new: $16.47 / Used from: $10.56
A little bit on all the common PNW critters
Plants and Animals of the Pacific Northwest: An Illustrated Guide to the Natural History of Western Oregon, Washington and British ColumbiaPlants and Animals of the Pacific Northwest: An Illustrated Guide to the Natural History of Western Oregon, Washington and British Columbia by Eugene N. Kozloff
Buy new: $25.55 / Used from: $4.55
Kozloff again, good for figuring out how to keep your inverts alive
Between Pacific Tides: Fifth EditionBetween Pacific Tides: Fifth Edition by Edward Ricketts
Buy new: $28.75 / Used from: $20.00
A great book for habitat specific aquarium styles.
Marine Invertebrates of the Pacific NorthwestMarine Invertebrates of the Pacific Northwest by Eugene N. Kozloff
Buy new: $32.58 / Used from: $23.50
More of an emphasiss on taxonomical identification of every invert. mostly line drawings and B&W photos