When delivering materials online, having clear instructions and expectations is vital.
One reason for this is that it can often be harder for the student to request clarification (example: they may have to send an email and wait a day or two before they get an answer).
Similarly, it is also important to have a clear communication policy with students. For example, students should know that if they send an email they can expect a reply within X amount of time, clarifying expectations such as this can be helpful to both student and staff. The student now knows they will get a response but knows it may not be straight away , while the staff member is not expected to be online all day everyday.