Hi @webiondev
Fo the SAS Certified Specialist : Base Programming Using 9.4 exam, free lessons are great foundations tool, especially SAS Programming 1: Essentials
I would also recommend the certification guide, as it really explains how SAS "works", and provides a lot of examples and practical scenarios.The most various situations you see, the most confortable you feel at the exam session
Here is the link to this book: SAS Certified Specialist Prep Guide: Base Programming Using SAS 9.4