There are a number of different ways that you can use the Control Systems Lesson Set.  How you use these lessons depends upon your individual learning style and personal preferences as well as the course situation you have.

• The lessons are organized like a book.  If you go to the main page of the lessons (Click here to start those lessons.), the menu at the left is organized into book sections.  Sections include "Basic Concepts", "Analysis Techniques", "Design Techniques", and "Nonlinear Systems".  Within each section are book chapters.  For example, within "Design Techniques" the chapters include "The Root Locus", "The PID Family of Controllers", "Robust Control", etc.  Within each chapter are individual topics that you can read.
• At the top of every lesson in a navigation guide.  That navigation guide tells you where you are within the lessons.  For example, it might read "Design Techniques - The PID Family of Controllers - Integral Control".  That information is put there to help you get back to material after you have used it.
• Every book has an Index.  In an Index, topics are presented alphabetically by topic.  If you go to the main page of the lessons, there is a button at the left that links to "Index of Topics".  Within that index entries are links to the various topics.  Those links might take you to a full topic, or to a particular sub-topic within a lesson.  If those links take you to a lesson, you can use the navigation guide at the top of the lesson to determine where you are.
• Your instructor may post course notes with links to topics under discussion in your course.  If those links take you to a lesson, you can use the navigation guide at the top of the lesson to determine where you are.
• Finally, there are some pages that walk you through a topic and provide links to the material you need to know on the topic.  These are not available for every topic, but, where available, they provide a good way to encounter a topic, and often have interactive simulators and calculators designed to help you learn the topic.