The Rules of Shooting. The rules of shooting can be found here, along with the changes implemented in March 2011.
GNAS Shooting Proceedures. Among other things this shows all the rounds and classifications in depth.
The 'Reference Guide for Recurve Archers', originally produced for Grange and Balbardie archery clubs by Murray Elliot. A very useful guide to choosing, setting up and shooting a recurve bow.
Rounds & Classifications. Here are some files that may be of interest to you. They summarise information about the rounds and classifications used in archery. With thanks to Phoenix Bowmen of Halifax.
Easton Tuning Guide. Arrow tuning and maintainance guide.