Erica Ridley’s newsletters are fabulous. They aren’t so frequent to be irritating, and they are always a nice break from whatever is going on in your life. She gives a glimpse into her personal life, then her writing life, and she actively promotes other authors’ works as well. There is often a freebie - be it a novel, a novella or a short story.
When it comes to writing companies or writing related brands, most of them are always pushing some product or service.
Alessandra Torre seems good value, and her facebook group is active. She runs Inkers Con (it must be happening soon), but she does seem focused on helping authors achieve visibility. Derek Murphy’s another who gives far more than he probably should. Then there’s the Alliance of Independent Authors - that’s a membership organisation for Indies, but it’s got a good rep with several authors I know. And Reedsy’s worth a mention too.