A collection of resources that might come in handy when you decide to create various visual material for your alternate history-themed works.
Public Domain Vectors.org - Royalty-free vector clip art and graphics.
Clonezone.link - Website editor that you can use to edit real websites to make fake ones, if anyone needs help with making fake websites.
Blueprints.com - A site with thousands of schematics for various civilian and military vehicles. Probably no fictional models, but you can download the schematics and use them as aid for creating your own AH vehicles.
Shipbucket.com - A useful little site with tons of pre-drawn pictorial models of various real and alternate military ships and various other vehicles of war. Can come in handy if you're creating a navy-centric TL.
Springsharp.com - “SpringSharp allows you to design “what-if” and “never built” warships between 1850 and 1950 using little more than the specifications in books like Janes Fighting Ships, Conway's All the World's Fighting Ships etc. It applies parametric formulas as used by professional Naval Architects (Mumford, Parsons, Holtrop & Mennen etc) as well as empirical data based on research on ships (Liners & Warships) of the period to give a soundly grounded and scientific basis to your designs. SpringSharp produces a written report in far more detail than the above resources.”
PimpMyGun site - A great flash application for creating pictorial models of various firearms (real modified ones or completely fictional). Has a rather extensive list of pre-built default models and accesories and is regularly udpated.
Pimp My Airsoft - Not as good as the above one, but with a little skill, you can still use it to make decent fictional firearms.
Another custom coin generator (WARNING : The site that hosts it contains some NSFW stock images.)
Make Your Own Soldiers and Other Military Stuff - Requires decent usage skills of programs to edit figures, once you get the hang of it it works fine. There are tutorials online. Updated every week with new figures.
MapSymbs Homepage - Tom Mouat's NATO Military Map Marking Symbols as TrueType Fonts, and other Military related Resources.
Ortelium Symbol Factory - Online generator tool for military map symbols (primarily NATO standards).
Resources by themselves don't create artworks, so you'll have to probably practice and learn certain skills before you create some.
Useful 1920s-1930s typefaces, newspaper resources, and telegram templates, courtesy of Color-Copycat
Tutorial for Making Alternate History Maps, courtesy of IntrepidTee
Modern-style map tutorial (using GIMP and Inkscape), courtesy of Kuusinen
Generic ship drawing guide, courtesy of the contributors to the Shipbucket.com forums
Flag and Vexillological Resources - A resource page.
Heraldry Resources - A resource page.
Map and Cartography Resources - A resource page.
Alternate History Media - A collection of threads containing alternate history artworks made by the members of the board.