Below you will find links to resources and information from all over the web. If you know of a useful resource not mentioned here, please comment below so we can add it

SCA

SCA Seneschals Handbook
SCA NMS Policy
SCA WaterBearer Announcement
SCA Insurance Certificate Ordering Instructions
Interkingdom Equestrian Competition page
SCA equestrian handbook

AnTir

AnTir Kingdom Law
Kingdom Reference Shelf
Kingdom Event Policy
An Tir Handbook
AnTir Forms List
AnTir Calendar Policy (2010)
AnTir Calendar Procedures
Curia and Financial Minutes
AnTir Check Request Form A form to request reimbursement
An Tir Equestrian Web Page
An Tir Book of Horse
Event Information Form (EIF)
Date Reservation Form (DRF) (yes, the EIF and DRF are the same)
Minister of Childrens Blog

Other resources

Autocrats have to be flexible - When you’ve just got to laugh about it
The Summits Event Handbook
The event stewards handbook from NorthSheild
Stefans Florilegium for Event Planning
Tell me about Autocratting an Event from Maitresse Anne-Marie d’Ailleurs