I figured I might as well.
Guide to Footmen
Guide to Archery
There is no real good guide to cavalry, so:
Always be aware of your surroundings. Watch out that you don't couch your teammates. Pack a good sword, and avoid riding broadside to archers. Also, some throwing weapons often come in handy on horseback.
Covering the Basics (Video) by Reapy
Dueling Guide
Despite the new Dueling Game Mode, still worth a read on how to act during a duel, and will familiarize you with general house rules for dueling.
Complaint Form for Official Servers
How to Set Up and Host Your Own Server
Overhead Map Views
Game Mode Definitions (Whole Thread)