The Family Historian User Group website (www.fhug.org.uk) is an excellent resource for Family Historian plugin writers. There is a forum for plugin writers (see FHUG Forum Plugins) and also a knowledge base section, which includes re-usable code snippets (see FHUG Knowledge Base: Plugins).
There are numerous resources available for Lua script writers available on the Internet. This page lists resources which are specifically aimed at Family Historian plugin writers. New resources will be listed here as they become available, so please check in here from time to time, to find out what’s new.