When you click on a course in your My Courses page you will see the title and a short description of the course. Below this you will see several links to the lesson material.

There is usually a link for viewing the PDF in your browser, a link for downloading the PDF to your computer, a link to a Dropbox folder containing all lesson material for viewing or download and then a link for downloading a zip file containing all lesson material.

The zip file is not recommended for download on mobile devices unless you have an zip file decompression app.