Once I start a course, do I have to complete it in one sitting?
No, you may go through any of the courses at your own pace. The course will track your progress and you can take a break and then pick up where you left off any time you would like.
Once I complete a course, can I still access the material afterward?
Yes, the courses do not expire. You can access the material any time after completion to review the course, or any portion of the course, again.