You're gonna have a great time.
I agree with doing most of your planning prior to leaving home. Bring the laptop if you see something that intrigues you but want to learn more about it before heading that way, or other quick things like that. But spend your time walking around the campground, enjoying the sights and visiting with other Rvers, not on the computer. In fact, those RVers can be a great source of information. You might find someone who has been, maybe even within the last few days, to where you're going and can give you some recent intel that might prove helpful.
I have a Benchmark for my state but I rarely find the need for one when one roadtrips as I usually dont have the time to go far enough off any main roads to need one. But they are pretty cool. I would check them out at the link Mark gave you or go to a good bookstore and look at them in person before ordering one as they can be quite spendy if you're buying for several states.
For the Oregon & Washington coasts, Olympic Peninsula, and Seattle areas:
A listing with links to several informative posts This should get you started.
From Seattle to Spokane, most people take I-90. It's a pretty drive but Snoqualmie Pass is really the least scenic of the passes. If your RV can handle a bit steeper grade, you might check out Stevens Pass. It's just a tad north of I-90s Snoqualmie Pass but far more scenic, imho. The best two passes are White Pass and the North Cascades Highway but they might be a bit challening for your RV. I do't know the grades but you might check out that info on them to see if they would work for you. If either works, do the North Cascades Highway. You won't regret the scenic views. And driving through the gorgeous Methow Valley on the east side of the mountains.
Between Seattle and Spokane, no matter what pass you take, you can easily swing up to Grand Coulee Dam. This is a must-see. Incredible. While it lacks the impressive tallness and the way it looks hooked to the canyon walls of Hoover Dam, it makes up for it in mass. At one time, don't know if it still holds true, it was the largest concrete structure in the world in terms of mass. Beautiful country, too.
Not far from it is Dry Falls. This is also incredible as it was the largest waterfall in the history of the planet, and the scab/coulee land around it is equally fascinating.
Hope that gives you some ideas. Keep asking questions.
There are several websites designed as travel blogs. And you could just set up a regular blog for free as well. But I don't have enough experience with any of them to make a recommendation.
We completed the trip and wanted to thank all of you for your excellent suggestions. We left Virginia Beach on April 17 and returned on June 7 traveling 11,001 miles almost all on non-Interstate roads. We had a blast and found plenty of "go back to" locations- probably enough for a lifetime! What a great country- the people and the sights. We certainly learned an awful lot and will be much better prepared next time, although I would have to say we really didn't have any significant problems this time. If anyone is interested, we put a sampling of our pics (actually captured over 4000 images) and included a map and calendar on the following site. Thanks again to all- this is a great resource and we will definitely be back for suggestions in the future!