There are very few SharePoint 2007 books on the market yet. It looks like a whole lot more are slated to be published this spring. As they come out I’ll try to publish my reviews of them.
Microsoft® Office SharePoint® Server 2007 Administrator’s Companion
This is a solid book for those who are familiar with what SharePoint can offer, and want to learn how to actually configure the server to do what they want. Because the book is geared toward IT folks, it covers out-of-the-box functionality in good deatil. I wouldn’t recommend this book for developers or folks already very familiar with SharePoint; the information is too basic to be considered reference material for experienced users. However, for first time users, it’s an excellent buy.