Imaginative Realism by James Gurney is a great book, I recommend it too anyone doing arts of any kind, even more so too fantasy illustrators and concept artists. This book covers a wide range of topics from Archaeology to People to Architecture (even has a section on dinosaurs, must have!)
I was doing a little doodling while reading through, mainly concentrating on the book! However I thought I'd post said sketchs, also the header picture from this blog. More sketch's to come soon!