First of all, it is possible to do the BC to Disneyland trip in 2 long days on the road. I've driven pretty much the reverse route (Orange County California to Bellingham WA and return) many times. However, with 10 days, you're going to subtract out at least 4 for just the trip up and back.

The fastest route is of course, I-5. A good place to break the trip is in the Yreka to Redding region of Northen California -- it's about half way. There are a number of places to stay in these towns, with Redding having the largest concentration. You do need to be a bit careful about timing your trip -- avoid the Seattle and Portland rush hours, since I-5 goes through the center of the cities. LA is a case in itself -- I-5 goes through the core of the city, so I usually take the 210 to 57 freeway to avoid going through downtown (or the 405, if you're staying south of Disneyland).

The Oregon coast will add a least a day heading south, and probably 2 depending upon what you'd like to see or do. Probably your best option would be an early start out of BC, and then down I-5 to near portland, then west to Astoria, and then south to spend the first night somewhere around Tillamook. From there it'd be about a full day south to near Crescent City or Eureka CA, which is in the middle of the Redwoods National Park, as well as the several California Redwoods State Parks. From Eureka its barely possible to make it to the Disneyland area in a longgg day's drive -- you won't make as quick of time on 101 than you would on I-5, but you will move along.

If I had to pick one or two places near the road to stop and get pictures... it would be Lady Bird Grove in Redwoods National Park, and the Richard Drury Memorial Parkway in Prarire Creek Redwoods State Park. Both are within a few minutes of 101 (Richard Druary parallels 101), and have a good selection of highly accessible impressive trees.

I'm not sure of what campgrounds are available in the Oregon coastal area -- just haven't camped along there. There are some I've noted, just have no experience with them.

There are many campgrounds in the Redwoods area -- I've stayed in Del Norte Redwoods State Park and a couple of other campgrounds farther south. You can check on site availabilty and get campground reservations on line. On the way south, the Yreka to Redding area has several campground options available near I-5.