For starters, it is always a good idea to begin a course with a text module that introduces the user to the subject of the course and briefly talks about will be discussed.
Missed question review is a very powerful tool for reinforcing training. If you're quizzing your staff on a subject, you wanna be sure they know why they got a question incorrect and what the correct answer is. Under each question, there is a missed question review section. You can include a small video clip here that talks out the topic, or you can type out some information that helps the user understand the correct answer. All of this information will become visible to the user when they get to the missed question review section of the course.
If the current section will not be graded using a submit and score option, take advantage of the immediate feedback fields within each question module, A user will know right away if they got the question correct or not, and be sure to include feedback for both correct and incorrect answers.
If your course will not have a test or a quiz at the end, place one to two questions after a piece of content in the course.
The skip end of section button at the top of the course can help speed things up via a rather long course with multiple sections. By default, this will pop up after each section in the course. If you're going to use submit and score, be sure all the questions that will be submitted are in the same section. The questions up there will not be graded in the submit and score here. This is because they're a different section. A course should only have a single submit and score module.