Various useful online or bibliographical resources concerning flags and vexilology.
Flags of the World - The oldest and largest flag database on the internet.
Proposals for European flags from Arsène Heitz (1952–1955) - Early 1950s proposals for flags of future European integration and its member countries. Available for free download as a full .pdf overview here.
A sampling of older (and usually short) discussions about flags that can help you with inspiration and critical feedback while you're creating your own. Please don't revive these threads, especially if they've been dead for years. We hope you'll find them useful.
Tools for creating illustrated AH content - A collection of tutorials, resources and recommended software for creating artworks.
Heraldry Resources - A collection of useful resources for creating maps and other cartographic stuff.
Map Resources - A collection of useful resources for creating coats of arms and other heraldic insignia.
Alternate History Media - An overview of various artwork threads on AH.com, for comparison and potential inspiration.