If you visit only one site, it should be the award-winning
Shorelands site, including all its links and downloads:

WA DOE Shorelands and Environmental Assistance
and be sure to check out these pages:
         Control Erosion Using Vegetation
         
Living On Puget Sound (Homeowners)
         
Managing Drainage on Coastal Bluffs
         
Managing Vegetation on Coastal Slopes
         
Puget Sound Landslides
         
Shoreline Management
         
Surface Water and Groundwater on Coastal Bluffs


Here is the second tier of most informative sites:

Greenbelt Consulting - Puget Sound Bluffs

PSAT • Puget Sound Action Team • Site Map
         Education and Public Involvement
         
Low Impact Development - LID
         
Puget Sound Shoreline Stewardship Guidebook

NOAA Coastal Services Center

NOAA Ocean and Coastal Resource Management


These are other useful sites, many specialized or technical:

BMP's - Best Management Practices
         
WA Forest Practices
         
Silvicultural Library and Database
         
Urban Water & Tree Related - NRCS

EPA - Environmental Protection Agency
         Region 10 - Puget Sound
         
Surf Your Watershed - Puget Sound

Jefferson County
         Community Development
         
Marine Resources Committee
         
Water Resources Council

Municipal Research & Services Center of Washington (MRSC)
         (Environment & Natural Resources)

NRCS - Natural Resources Conservation Service
         SOILS - Tools for Educators
         
Soil Biology Primer
         
WA Soil Survey Reports

Puget Sound Nearshore (Restoration Project)

Puget Sound Regional Synthesis Model (PRISM)

Puget Sound Nearshore Science Team

US ACE Index of Engineer Manuals
         See Coastal Engineering Manual and Slope Stability
     or
US ACE CHL Coastal Engineering Manual

USFS Silvics of NA Manual

USGS - U.S. Geological Survey
         
Ground-Water System Chimacum Creek Basin
         
Coastal and Marine Geology Program - Pacific Northwest
         
Formation, Evolution, Stability Coastal Cliffs - P1693

WA DFW - Department of Fish and Wildlife
         
Priority Habitats & Species Management Recommendations
                  (
see Bald eagle)
         
Bald Eagle

WA DNR - Department of Natural Resources
                  
Water, forests, geology, hazards, and land management.
         
Backyard Forest Stewardship - Western
         
Forest Practices Board Manual
                  (Guidelines for Evaluating Potentially Unstable Slopes)
         
Urban & Community Forestry

WA DOE - Department of Ecology
         
Washington's principal environmental management agency.

WA Water Quality Guide Home/Farm

WA DOE WRIA 17 - Quilcene-Snow (Kala Point's Watershed)
     and
WRIA 17 Quilcene-Snow Watershed Project

WA DOT - Department of Transportation (Environmental Services)

Eagle Protection in WA - Julie Stofel, WDFW Region 4
         
(This is an unofficial FAQ for a homeowner association)

WA Native Plant Society

WA Sea Grant Program
         See
Coastal Development; Ecosystem Health

USGS Puget Sound Lowlands Hydrogeologic

WA State University and Extension
         
Native Plant Landscaping - Western WA
         
NW Native Plant Guide
         
Washington's Water