This is probably my favorite magazine. It helps teachers, parents, and students explore different aspects of Computer Science in a very accessible way. The focus is on learning to code.
The MagPi is a fanzine for the Raspberry Pi. It includes articles on programming, electronics, robotics and much more. There are also news articles on #picademy, Pi clubs, and Raspberry Jams around the world as well as amazing projects such as "Astro-Pi" which sent a Raspberry Pi to the international space station with student programs.
MicroMag is the unofficial magazine of the BBC micro:bit. It is brand new, so a more detailed review will be forthcoming!
Make Magazine is not specifically tech-related, but is a great addition to any library. It focuses on Maker culture of all kinds and every issues includes detailed projects of varying complexity. There are often tech components to the projects.