For those of you waiting for the new "Inside SQL Server" book, it is actually out now.  Kalen decided to give it a name change, and the actual title is "SQL Server 2008 Internals".  I've written a chapter on how the Query Optimizer works.  It is currently #1 in the 3 related database/sql server categories on Amazon, so I'll say "thank you" to those who have already ordered a copy ;).  Like my blog postings, there are a lot of sample scripts you can try so that you can "see" what the optimizer is doing - I find this technique to be a very good way to learn what is happening, and I hope it works for you.

http://www.amazon.com/Microsoft%C2%AE-SQL-Server%C2%AE-2008-Internals/dp/0735626243/ref=pd_bbs_sr_1?ie=UTF8&s=books&qid=1237753244&sr=8-1

Enjoy!

Conor Cunningham