It is important to communicate to students how the learning activities help them achieve learning objectives as well as how they should use each of the materials. However, there is no one-size-fits-all way to achieve this. Below are suggestions on how you could achieve each of these goals. You often do this in class when you say "In this test or this paper, I am looking for you to demonstrate that you know how to (objective)..." Try to replicate that same kind of explanation in your online class assignments.
It is important that students understand what the relationship is between the learning activities and the learning objectives. This helps them understand how each activity, assignment, or assessment helps lead them to mastery of the learning objectives. "Learning activities" is a broad term, and it can include everything from a self-assessment on a textbook chapter to a summative midterm project. The important thing is that students understand once they have completed a learning activity which learning objective they have achieved (or are working on achieving). This is true for both module level learning objectives and course level objectives.
There are a variety of ways you can accomplish this, and the examples below are several possibilities. Feel free to pick from this list, adapt an idea from below, or create your own strategy.
Names matter. Try to name everything in your course explicitly so students know "this lecture covers this objective, or this video helps explain how to (something). If students need to progress through the course in a certain order, explain this. Do not assume students will work "top down" as it can be easy to find something such as a discussion on another tab. The student might join an active discussion without first viewing an important lecture.
It is also important that students understand the purpose of the instructional materials being provided, and how you intend them to use the resources. While this is often implied in the way that you organize your Content modules, students often don't pick up on your intentions for them to complete activities in a certain order unless you make that intention explicit. Therefore, you can use the examples below to help you communicate the purpose of the instructional materials and how you intend them to be used. As with the how learning activities relate to objectives, the examples below can be used in their entirety, you can adapt these strategies, or you can come up with your own methods.
These suggestions will help you achieve QM Standards 2.4 and 4.2.