https://www.craftsy.com/sewing/classes/beginner-serging/35609?

Keep an eye out for when this class goes on sale periodically.
This is a great overview for beginners. You can take it online or buy the DVD $29.99 

Amy Alan Serger Lesson on Youtube

Though she uses a higher end Brother model of serger, the procedures demonstrated work the same way on all Brother serger models.

Decorative Thread trick at about minute marker 5:25

https://youtu.be/o8VHoWwPcDo