Take your syllabus, your TOC, and all the resources you want your learners to read and then think how you will organize that content in your Moodle course. Just by picking up this book, I know you've thought about putting your content online and you have some ideas about how you want to extend your conventional course. Don't feel you need to do anything novel and extraordinary; often that isn't the best strategy. Never compromise your teaching methods just because you're using a different form of delivery. After all, Moodle is designed with pedagogy in mind. You can structure your course by weeks, topics, or discussion and build from there.
Thinking and working through exactly how you're going to deliver the teaching are harder than actually doing it, and in my opinion, the delivery is the most critical aspect of any successful course. Your syllabus is a great starting point. Have a look at a few demo courses, plan your course (storyboards are a good tool to help plan), and then begin. The companion Web site offers few planning templates that may help.