I don't know how much help this will be, and I'll be happy to go look up specifics if you need for me too . . . but I was in Oregon and northern California on the coast for nine months last year and early this year. I came into Washington from Canada on the way back from Alaska. I stayed at a KOA in Seattle and at an RV park on the river just as you cross into Portland on the right. I came across to the coast from the interstate in Newport, I believe, and drove down Highway 1 towing a very heavy Teton 5'er and I don't think I would do it again! And I drove up Highway 1 from San Francisco too at a later date - the scenery was breathtaking. Great wineries too. I did that in my car - wouldn't advise a large RV on some of those roads - if I remember correctly, they don't allow RV's on a lot of them.
There's a little town called Ferndale south of Eureka that has been the site for a lot of movies. It has victorian buildings and homes in pristine condition, a charming little town, great restaurants and a beautiful drive out to the beach as well as a great hike down to another beach. If you do nothing but drive through the city, it's a treat. There's an RV park at the Fairgrounds - it's not great but it's cheap and you have water and power. You can see the coastline from there. The movies "The Majestic" with Jim Carrey and "Outbreak" with Dustin Hoffman were filmed there.
The nicest RV park in northern California in my opinion was Sounds of the Sea in Trinidad. It's right across the street from a bed and breakfast and you can see the ocean from some of the sites. They even have private terraced sites on a hill with a view. Rates were very reasonable too. Patrick's Point State Park is across the street - a great hike to Agate Beach. The little town of Trinidad is charming with great restaurants, beaches and views. There's an Indian Casino there where you can hook up to water only and stay for a week. Stay away from the Eureka area - there's one fairly decent RV park there - Wild River - and definitely avoid the Klamath area - especially Kamp Klamath RV park. The whole city is a dump - high crime and junky. It's Indian land and the Indians had opened a casino there, the casino closed, the economy is rock bottom and there's nothing there but a bar, few RV parks, a restaurant, laundromat, post office and shoppette. Lady Bird Johnson Grove in Orick is a MUST SEE - you walk through the redwoods.
Between Klamath and Crescent City, there's a little RV park with a red barn . . . cannot remember the name (darn!!) but Elk graze there and come right up to your RV. Across the street is another spectacular beach. Also Avenue of the Giants is another great drive through the Redwoods. Crescent City has a few nice RV parks - the ones near the water aren't too great but very convenient for sight seeing. Brookings has several RV parks that are either on the water or near the water. Sorry - but my senior brain can't remember the names right now.
Brookings is a really neat little town too. If you need to shop, shop in Eureka or Brookings - not much once you pass the Oregon border on Hwy. 1 at least. There's a little city every 25 miles, but no discount stores.
Turtle Rock in Gold Beach is a neat set up - you're protected from the high winds by the highway but there's a trail to walk to the beach underneath the overpass and the town is really cute.
You will probably experience some strong storms. They were all bearable except for the one right after the 1st of December last year - it tore off some awnings, roofs and knocked some trees down. I'd advise you to stay in RV parks that are protected - like Sounds of the Sea - or parks not right on the water. But take a rain suit and drive out to see the storms when they hit. SPECTACULAR. If you want to run the names of some parks by me, I was familiar with most of them and will give you my input on them. You'll love it - it is sooooo beautiful there that time of year - in between the rains the weather is pleasant and the beaches are awesome. If you like beautiful rocks, agates and jade, you're in for a treat. Oh - and some of the most gorgeous driftwood I've ever seen. ENJOY!!