Without doubt, the best boondocking guide is the Days End Directory which is available to members of Escapees RV Club
It is the only guide we use, and we boondock nearly 100% of the time.
The way we work with the directory is to search it for keywords like "view" "pretty" "beautiful" and then we highlight those locations and look them up on the map.
We usually use one of those sites as a starting point. After parking for a day or two we get on our bikes or take the truck and scope the area out to see if there's something better. Usually there is!!
There are tons and tons of spectacular places to stay with views that are to die for. But the best way to find them is to hunt them down in person rather than online or through a guide.
The guide is best used as just that -- a guide -- but rely on your own explorer's initiative to find the best places... It's so cool to find a really awesome spot on your own -- for us it's half the fun of boondocking.
I've written a few pages on our website about boondocking and setting up your rig for solar and conserving electricity and water... maybe you'll find those pages helpful... they're under the Lifestyle menu button