SQL Server 2008
So here is my first book recommendation in this blog. The authors (Chris Webb, Alberto Ferrari and Marco Russo) are all well known Analysis Services experts and they did a pretty good job in writing this book. It is fully packed with information, tips, tricks and recommendations. The authors also reference not only the core Analysis Services features but also provide useful links to other tools like BIDS Helper or MDX Studio.
You can find the book and more information about its content in the Amazon book store.