Vinod Kumar and Pinal Dave have just published a new course: SQL Server Performance: Introduction to Query Tuning

SQL Server performance tuning is an art to master – for developers and DBAs alike. Vinod and Pinal take a systematic approach to planning, analyzing, debugging and troubleshooting common query-related performance problems. This includes an introduction to understanding execution plans inside SQL Server.  They discuss and demonstrate writing queries in an efficient manner, and making sure they execute in the most optimal way possible, which is always a challenge. The basics revolve around the details of how SQL Server carries out query execution, so the optimizations explored in their course follow along the same lines.