A few thoughts to add to what has already been posted.
The early zines for me in the UK back in the late 70's that help illustrate how the game progressed were Underground Oracle and Trollcrusher. Both of these I think were formative in creating a template for those that followed, and some contributors to Trollcrusher later launched their own zines. Hartley Patterson's News from Bree was also influential. After that, I'd put The Beholder (which did go through multiple reprints, it proved so popular), Demonsblood and Illusionist's Vision. I dropped out of the hobby in about '81, so my own experience doesn't extend to those that followed like Tortured Souls and Imagine.
And if you're not just looking at fanzines, the articles and letter columns in the early White Dwarfs are good sources.
You might also find Joe Nuttall's blog of interest. He chronicled early D&D scenarios, including many that were first published in UK fanzines, and traces how they developed over time. The blog can be a little difficult to navigate but this link runs a search on his blog for that content:
explorebeneathandbeyond.blogspot.com/se ... +scenariosAlso RPGgeek has many fanzines in its database, most with content listings and date of publication. For example, here's the one for The Beholder:
https://rpggeek.com/rpgperiodical/2462/the-beholderHave fun! It was a rich period in the history of D&D.