Database Administration and Business Intelligence is indeed very key area of the SQL Server. My very good friend Ross Mistry and Stacia Misner has recently wrote book which is for SQL Server 2012. The best part of the book is it is totally FREE!
Well, this book assumes that you have certain level of SQL Server Administration as well Business Intelligence understanding. So if you are absolutely beginner I suggest you read other books of Ross as well attend Pluralsight course of Stacia Misner. Personally I read this book in last 10 days and I find it very easy to read and very comprehensive as well.
Part I Database Administration (by Ross Mistry)
1. SQL Server 2012 Editions and Engine Enhancements
2. High-Availability and Disaster-Recovery Enhancements
3. Performance and Scalability
4. Security Enhancements
5. Programmability and Beyond-Relational Enhancements
Part II Business Intelligence Development (by Stacia Misner)
6. Integration Services
7. Data Quality Services
8. Master Data Services
9. Analysis Services and PowerPivot
10. Reporting Services
Here are various versions of the eBook.
Reference: Pinal Dave (http://blog.sqlauthority.com)