Most of these are some that I really recommend you look into!

Retro Tech Lounge [http://retrotechlounge.com/] is a very neat site for utilities and other things!

Glitter Graphics https://www.glitter-graphics.com/ is an useful website for when you need some graphics for the page!

The Virus Encyclopedia http://virus.wikidot.com/ is a website dedicated to documenting information regarding computer viruses and their history! You may have seen them being mentioned before on this site, I'm simply still in awe from it all.

Cameron's World https://www.cameronsworld.net/ is a project that showcases the art of the old web! Check it!

Web Design Museum https://www.webdesignmuseum.org/ is a website dedicated to showcasing the old designs of the websites back in the days!

Webopedia https://www.webopedia.com/ is a site which holds everything about the web you'd want to know! Well, almost.

WinClassic https://winclassic.net/ is a forum dedicated to all things Windows and Classic!

TigSource https://forums.tigsource.com/index.php is a forum dedicated to independent game development!