I’ve lived in the Pacific Northwest for a decade now and find myself using the same resources over and over again. That’s because they’re incredibly useful and informative. I use a combination of the web and print materials to plan my trips and fantasize about what may become.
One of my go-to’s is the website Northwest Hiker. There’s a real wealth of information here. My favorite part is the extensive list of hikes organized my geographical location. Along with a description or the hike and how to get there, pictures for various points along the trail are included, embedded on the map of the hike. Northwest Hiker also has links to local weather and even a daylight calculator among other interesting features.
My other online fav is Oregon Hikers which is something to write home about. They also have a huge compendium of hikes and very useful info, however the real strength of this site is the active forums. You’ll see lots of great trip reports and the community is pretty friendly and open. This is also my go-to especially for off-trail reports and mysterious places.
As far as print material goes (aka books) nothing beats William Sullivans region specific guides for hikes of all types. I own a few for the regions I frequent and they are really great for finding new hikes. They cover Oregon and SW Washington. Each book has 100 hikes, but also includes an appendix in the back of many more hikes that didn’t make the cut (but that nobody takes). I let him know once that a trail had been rerouted, and he sent me a free copy of one of his books just for letting him know!
The final resource I use are just the maps that I already have of various National Forests and Wilderness areas, and my DeLorme Oregon and Washington Gazetteers. This is by far the most effective way to find new places to visit. I just pore over the maps until I find a new loop or area to explore by foot, bike, or car. Its easy and fun. Choose your own adventure.
There are many other resources, but these are the ones I go back to time and again, hopefully you enjoy them as well.