There're 2 authors - Ken Henderson and Kalen Delaney - whose books are SQL Server bible for me and, I believe, to many other SQL Server DBAs. Now there is only one left - Ken Henderson passed away last Sunday.
First time I've seen "The Guru's guide to SQL Server" series, I was amazed, how the book can be at the same time so deep - and so clear. Books usually speak about everything in general - and nothing in particular. When DBA needs to drill down into some topic - he usually looks for articles on the net. "The Guru's Guide" series is an exception - level of drilling down into some topics that Ken Henderson reached in his books is truly amazing. Rest in peace.