The Art of Thor is a 240 page hardcover art book that comes with a slipcase. The cover has a faux leather texture with the title embossed and a sticker of a piece of art pasted. The paper quality is like thicker magazine paper, just like the Iron Man movie art books, also published by Marvel.
If you haven't watch the movie, the spoilers in the book will come in the form of characters that aren't shown in the trailers. There are lots of designs for the characters, namely Thor, Odin, Loki, Destroyer, enemies and other lesser characters. Each character has several costume variations. The armor and especially the helmets are very beautifully designed. The costumes designs are done really well. Designs for the Destroyer is very cool.
The environment art are on Asgard and its various places like Odin's chamber, palace ground, Heimdall's Observatory, Jotunheim and also the sets on Earth. They aren't digitally painted - touched up definitely - and have a very CGI look with the photo textures. The concepts and design are great, you get the feeling that Asgard is a beautiful place but somehow the style of the art just doesn't bring that out.
The rest of the book have other stuff like designs for the hammer, Odin's horse, photos of the props and actors, movie posters etc. Most of the art are accompanied by commentary providing interesting background information, like why they create runes on the hammer and what they are.
The downside of the book is the less than satisfactory resolution of the art included. The image resolution isn't high enough for the large format book. Some of the pictures look pixelated, especially for those that are scaled over 2 pages, typically the background art.
So overall, the character art is great, but the background art and low image resolution don't quite make the mark for me.
(There are more pictures of the book on my blog. Just visit my Amazon profile for the link.)