Use the workbook and encyclopedia in combination with each other, they were made that way and you learn a lot by using them both.
Make sure you have The Wheel, or have access to one, as you will be asked questions that involve its use.
Keep track of your skills score yourself with pencil after every pool or open water session, if you get a 3.5 and think you can do better, don't be afraid to ask to redo the demonstration skill. Once you have gotten the skills down and scored well, fill in the scores and have the instructor sign it. In short, keep track of your progress, this will free up the instructors time and help progress you faster through the course.
If you have good instructors, be prepared to work your butt off, they will task load you. A good DM is nearly indispensable to an instructor; they do all the "other" stuff, leaving the instructor free to focus on teaching safely and effectively.