We sell to schools, so the main buyer will be the contact associated with the deal, but all the teachers are the end users who I have listed as contact roles on each deal.  We cannot figure out how to email all the end users for a deal.  They need to know when their account is renewed and receive check in emails etc.  Ideally I would like to edit a field in the deal that will trigger a workflow to auto send emails to them over a period of time.  Any help would be appreciated.  If coding is required - I am not a developer, so you will have to spell it out step by step for me ;-)

I would prefer to use the existing contact roles in Deals, but i can also use a multi-lookup field too, if the solution is easier with this.