I really like this: http://virtual-anaesthetic-textbook.com/
It reviews the basic sciences relevant for anesthesia, tells you about machines and monitors and also about the management of special patient groups.
I guess the standard that attendings recommend is Basics of Anesthesia, by Miller (this is the Baby Miller). But there hasn´t been a new edition in a while.
Clinical Anesthesiology (Lange Series) has a more recent edition, and many residents like it, but it looks like it is a bit longer than Baby Miller.
Many Residents also recommend Anesthesia Secrets, just like Hawk22 said. But if I remember correctly, it is a question and answer format, maybe not the best for a first overview.