I subscribe to (and unsubscribe from) a lot of newsletters. What I look for in a newsletter is good information that makes me think, or which I can use in a practical way. The following newsletters are the best of the bunch -- except for my own of course!
Mirandanet newsletter
This is a monthly round-up of ed tech news. Very informative. I don't think you have to be a member of Mirandanet to subscribe, but it's free to join anyway and very worthwhile. Here are the links:
The Whiteboard blog newsletter
This is a monthly round-up of the articles that have appeared on the Whiteboard blog. Although the term 'whiteboards' sounds a bit old-fashioned these days, the blog also covers other interactive devices, apps, augmented reality and VR. It tends to have a leaning towards Science, I've noticed. Definitely worth subscribing to. Just head over the the Whiteboard blog and a pop-up will, er, pop up, enabling you to subscribe right away.
Nik Peachey's Education Technology and ELT newsletter
This consists of loads of links to articles. I like the fact that Nik is prepared to link to articles he doesn't actually agree with. So, you get plenty of reading matter to choose from. Here's the link: Education Technology Newsletter.
Finally...
Oh well, since you've twisted my arm, here are the details of my own newsletter, Digital Education, and a couple of others: Newsletters.
I hope this post has given you enough reading to be getting on with!