Old newspapers: Believe it or not, print media wrote about video games quite a bit, and that’s not even counting advertisements! Websites like newspapers.com and newspaperarchive.com have quite an assortment of old papers from across the US and Canada that you can keyword search.
Industry trades: These can be difficult to find online, but research libraries often have some of them. These include outlets such as Merchandising and Weekly Television Digest, which are excellent sources on the retail and consumer electronics industries, respectively; Toys and Toy & Hobby World, which covered games from the toy industry perspective; and rarer, esoteric stuff such as Electronic Engineering Times, of which very little survives but snippets and references in other outlets.
Game magazines: This one’s probably familiar to a lot of people – coverage in mainstream magazines such as Electronic Games or later ones such as EGM or Game Informer, as well as obscure sources such as Video Game Update & Computer Entertainer, or game-related coverage in magazines like Video or Creative Computing. A lot of these have been scanned and uploaded onto the Internet Archive for ready searching, and others that have been pulled down from there can be found… elsewhere on the internet. A literal torrent of information at your fingertips! Some physical research libraries have items too, including the University of Michigan’s Computer and Video Game Archive. The ongoing Retro Gamer magazine continues to get some solid interviews, and if you read Japanese, Famitsu does too. For the more academically minded, consider ROMchip, a game history academic journal. As of this writing the Video Game History Foundation is putting together its online library, which should prove to be an excellent resource for researchers unable to make the trek to a physical location.
Physical archives: There are several archives across the globe focused on various pieces of video game history, and often retain internal documentation or other materials helpful for research. Some highlights include the Strong Museum of Play in Rochester New York, the Hagley Museum and Library in Wilmington, Delaware (which includes distinct websites for video game materials); Stanford University in San Jose, California; MIT in Boston, Massachusetts; the Game Preservation Society in Tokyo, Japan; the Library of Congress in Washington, DC; and the Video Game History Foundation in Oakland, California (this is not by any means an exhaustive list).
Books: There are some truly fantastic works on video game history out there. There is, of course, my own book to start with. Historian Ethan Johnson has put together a list of game history books that’s worth browsing, and some of my favorites include They Create Worlds: Vol. 1 by Alex Smith, The Sega Arcade Revolution by Ken Horowitz, and, as a snapshot of time, Embed with Games by Cara Ellison. Remember, if you can’t afford the book yourself, see if your library has it or will get it for you!
Websites: Plenty of excellent video game history websites out there! Gaming Alexandria is a top notch one, as is the VGHF’s page. Similarly, I can recommend the Gaming Alexandria Discord server, which as of this writing has over 1,200 members – you can find people there interested in pretty much any aspect of game history you can think of. Other worthwhile sites include:
All in Color for a Quarter, which focuses on early coin-op video game history;
Bally Alley, practically a one-stop site for information on Bally/Astrocade’s Professional Arcade game console, including hundreds of games made by users back in the day;
One Million Power, where Japanese game- and music-related articles and interviews get translations;
Atari Compendium, a collection of interviews and articles from the early days of game history;
Blue Sky Rangers, the history of Mattel Electronics and the Intellivision from the folks who worked on the game development side;
Atari History Timelines, an exhaustively researched timeline of all the various Atari entities put together by Michael Current;
The History of How We Play, articles about various pieces of game history;
Shmuplations, another site with a lot of translated articles and interviews;
They Create Worlds, the website of Alex Smith, who wrote the game history book and co-hosts the podcast of the same name;
The Obscuritory, which delves into obscure games and multimedia experiences – usually (not not necessarily) strange and interesting stuff from the early CD-ROM era of PCs.
If any of these sites go down by the time you read this, I’d highly recommend seeing if the Wayback Machine on Internet Archive has captured them, because these are excellent sources.
Podcasts and videos: Podcasts and videos can be a great way to learn about game history topics, and interviews or keynote recordings are an excellent primary resource. The aforementioned They Create Worlds podcast is a good resource, as is the Video Game History Hour and Retronauts(to which I am a contributor and rotating host). For specific platforms, there are also excellent podcasts such as the Intellivisionaries or ANTIC. For videos, there’s my own work under Atari Archive, as well as many other well-researched channels online, including the Gaming Historian, A Critical Hit, Kelsey Lewin, and Jeremy Parish. Seattle Retro Guy has a slew of keynote recordings from Portland Retro Gaming Expo and Classic Gaming Expo that I’ve pulled from as sources, too.