Books are great references, and can be an effective learning tool.
The Reference Set
These books are canon for SQL Server developers and administrators.
Microsoft SQL Server 2008: T-SQL Fundamentals
Microsoft SQL Server 2008: Internals
Microsoft SQL Server 2008: T-SQL Programming
Microsoft SQL Server 2008: T-SQL Querying
Performance Tuning
These are the three best books I’ve found for performance tuning.
Professional SQL Server 2008 Internals and Troubleshooting
SQL Server 2008 Query Performance Tuning Distilled
Database Design
These are the books I always use when doing development or architecture work.
SQL Server 2008 Transact-SQL Recipes: A Problem-Solution Approach
Pro SQL Server 2008: Relational Database Design and Implementation


