Many of these videos are outdated, and remain here as a historical reference.
The primary video series starts at "Setting Up A Local Test Server and Your First Task Script" and ends at "Putting It Together: NPC Guides", with videos in order, labeled from 1 to 28.
All videos outside that series should be considered very outdated and historical.
that series are outdated but still somewhat valid in year 2019.
A replacement video series will likely be made in the near future - when it is made, it will be posted on the Denizen forum