I believe there is supposed to be a video on optimising the content of your page and using Google Keyword before the video on Media and Links. Rachel alludes to this in the previous video and it is mentioned in the conclusion video but there is no video covering these topics.
Thanks for asking your question at Envato forum
You can try with Envato Tuts+
hope it will helpful for you.
You can study here to know about optimization
Ummm I’m aware their is other content on tuts plus. I am informing you that a course has missing video and you should fix it.