Welcome to the support center of VirversitY as well as all partner course websites. Here is where you can find answers to technical questions about the course software and specific policies/questions related to any particular partner course website.
Use the sections and the subsections. This is what I do to keep lessons a reasonable length. Technically, lessons can be any length and long lessons are not a problem as long as the content is divided in smaller parts. For example, if your lesson is 3 hours long, but your presentation is 20 minutes, and you have 8 other videos that are 20 minutes each, that is not a problem. You just want to keep in mind the average attention span of a student is not that great.