Erm... there is so many things you could do with courses, so many tools you could use but consider this, form follows function. What are your learning themes? Two learning themes may be similar, so that may be a single course, but more likely not. The is all sorts of varieties and flavours here, so it's pretty much your own choice.
Your workbook has chapters so it might be one chapter dictates the content of one course. Say a Maths book has a chapters on trigonometry, Pythagoras and Algebra, and while similar in many ways, you won't create one course for all three chapters, well I wouldn't gets too messy. A course can have lots of learning outcomes, but it should only have one theme.
<span style="waxing: lyrical;">You have a work book, with chapters each with their own assessment items. If you were to copy that book precisely, then you might be opening yourself to copyright breaches, so be very careful. Cease and desist orders can be very expensive. We all face these issues and how we respond to them is an individual choice. Some foolishly, blithely ignore the issue, others, like me, just love reinventing the wheel so might use ideas from a number of different sources, but we create our own resources and activities. I learned long ago that it is OK to leave behind a body of work for others to use, even if they are people whom you are leaving them with are erm... not very likeable, shall we say. Pick your own level, something you are comfortable with and try not to plagiarize too much. Look for resources that have a Creative Commons seal on them, modify them for your own use, don't just use them as they may not suit your cohort of users, or may be about the mark but not precisely target your learning objectives. It's a lot of work, but it becomes easier to maintain that than it is to create it. </span>
The Moodle Docs are a good place to start, Managing a Course has good information. Adding activities has another set of pages. You can't have Activities without Resources. Understanding the differences between each type of activity and resource will help you figure out what you want to use in your course. Initially, remember the KISS principle, it's all about building your confidence with an unfamiliar tool. If you are confident in your work, then your students will be a lot more relaxed about this brand new tool. They will still push back, but if you sound like you know what you want, and keep a consistent message about using Moodle, they will come around.
Some of the questions you are asking already are a lot further down the track than your knowledge of the tool will allow for easy understanding. Groups are simple, once you understand how Roles work, Yes, you can use one course for as many different classes at the same time without an administrative nightmare, using Groups, or, my favourite, Course meta-links. But don't rush it, Moodle is a big and can be subtle tool and will trip you up if you try too hard.
Aghh enough.... Good luck...
