The title says it all: Everything You Wanted To Know About The Arquebus. I found this to be a good and interesting read.
Here’s a nice tutorial on making gabions and wattle fences.
Outlaws and Highwaymen is a terrific site loaded with information about English criminal history.a
Here are a set of useful pages with information on gaming the Reconquista.
The Conquest of Mexico is a period I’ve always wanted to game. Steve’s Balagan website has a very useful web page of information and links to resources on the Aztecs and other inhabitants of Mesoamerica.