These videos are superior to anything that I can do in a lecture format, so I will step aside and let them do the far better job.
That said, read pages 101 - 105 in the Lab Manual before watching the videos.
The graded homework assignment is also covered in Chapter 19 of the text
Go through ALL videos and text before attempting graded assignment on Launchpad
Watch this one first. The first half is a terrific summary and review of the course (hint, hint!), and the second half takes you through the development of the Big Bang Theory.
This video is a great recap of the concepts discussed in the previous video, from a slightly approach.
This walks you through the Big Bang timeline microsecond by microsecond.
(4) Parting thoughts from the physics course, but certainly relevant here...