Recommended Reading 

Book Author
Encyclopedia of Northwest Native Plants for Gardens and Landscapes by Kathleen A. (Kali) Robson, Alice Richter and Marianne Filbert (with additional photos by Dr. Sally Simmons)  A one of a kind reference for Gardening with Northwest Native Plants - HIGHLY RECOMMENDED!!!
Moss Gardening George Schenk   
Gardening with Shade Sunset Books   
All About Shade Gardening Ortho   
Gardening in the Shade Better Homes & Gardens   
The Natural Shade Garden Ken Druse   
The Hosta Handbook Mark R. Zilis  
The Natural Habitat Garden Ken Druse