We saw the Oregon coast for the first time last September, OMG! We came through Portland down through McMinnville to the coast and took that all the way to SF. What a trip, do yourself a favor and take your time there is so much to take in! Absolutely breathtaking, going from north to south is easier but I think it would be easy enough to cross over into pull outs heading south to north as mentioned before.
Definitely plan on taking in Northern California and the Redwoods. As long as your that close it would be a sin not to take that in as well.
Enjoy your trip, you won't be disappointed! BTW we tried to stay at state parks but that wasn't happening, once you get there you'll fully understand why.
Dan