Not the best Redon book, but it'll have to do, as the one I really want is now a collectible; but this one has the added advantage to me that I actually saw the show in NY and have some memory of what the charcoals and lithographs actually look like.
Redon was a dreamy guy with a dreamy name and his art rarely touches on the "real" world (quotes added for people who don't consider the worlds of the imagination real). His colorful, ambiguous, revery-inducing pastels are probably his best and best known works, but the dark charcoals and lithographs (which this book mostly features) are filled with worlds within worlds of shadows, the subtler qualities of which are unfortunately lost in reproduction.
There's also something eerie about Redon, especially in his human figures, when there even are any. Not only are they terribly stiff and flat, they are rarely if ever looking at the viewer. Most are either in profile or looking down or averted in some way. And none are ever making any noise. One even has two fingers over his mouth indicating silence. These qualities of his figures emphasizes the elusive inner world nature of the works.