Welcome aboard the RoadTrip America Forums!
One of our Moderators is from the Pacific Northwest and has written extensively over the last couple of years on the wonders of the country between Vancouver and, say, San Francisco. I can't add anything to her wonderful accounts, but I can gather up links to some of the best of them for you:
Add a Day or Two (Lake Quinault, Hall of Mosses, and other Olympic Peninsula sights
Enough for Two Months (areas of WA & OR away from the coast)
Awesome Trip (good overview of mountain areas including MSH, Crater Lake, and the coastal highlights)
Great Honeymoon (Grand Coulee, MSH, Mr. Rainier, Olympic Peninsula focus)
Go For It (natural attractions - mainly WA coast, a bit on Oregon coast)
Yup, It's Worth It (general WA/OR overview)
You're Gonna Have So Much Fun (Idaho/WA/OR overview)
Farther south, between San Francisco and Los Angeles, the road of choice is the Pacific Coast Highway (PCH), covered at some length here. If after reading through all that, you still have questions, by all means let us know and we'll see what we can do for you.