The TRRA does good webinars pretty frequently and posts them on their site.   A couple of them are unavailable when I click on them for some reason, but the content is available for most of them.

Topics include:

• Referee Development Through Self Assessment
  
• Tackling the Breakdown
  
• Setting the Scrum
  
• Assistant Refereeing
  
• Effective Communication
  
• Technical Zone & Assistant Refereeing
  

England rugby has a referee resources page with some online courses about the scrum and the tackle and about preparing for whatever their first referee course is. 

The Bay of Plenty referee society has a page with an online course on introduction to refereeing rugby.  There is a downloadable workbook and a series of videos.  The modules are:
Contents:
Introduction and Welcome
Module 1: The Role of the Referee
Module 2: Fixture Organisation
Module 3: Whistle! Signals! Verbals!
Module 4: Where do I stand?
Module 5: The Kicks of Rugby
Module 6: Tackle Ball carrier brought to ground
Module 7: Ruck and Maul
Module 8: Scrum
Module 9: Lineout
Module 10: Offside and onside in general play
Module 11: Foul Play
Module 12: Advantage, free kicks and penalty kicks
Module 13: Assistant Referee/Touch Judging
Module 14: Method of scoring – ingot


I don't love their list of reasons for becoming a referee, listed below.  I'm pretty sure it's not a comprehensive list.  But the course looks pretty good for a beginning ref.

• Are You A Current Player Thinking Of Hanging Up The Boots?
  
• Or Maybe You've Suffered An Injury But Still Want To Stay Involved?
  
• Or Maybe You Weren't Very Good As A Player But Still Want To Contribute?
  

The USAR referees resources page also has a bunch of training videos like the one I posted yesterday on various topics.  At least some of them seem to also be available on Vimeo.  Let's see how many of them I can put on this post before Weebly complains.