The LEGO LIFE magazine is released quarterly and it seems like it’s mailed free of charge to kids aged 5 till 9 4 times a year. It contains comics, activities, posters, alternate building instructions and more.
All you need to do is sign up with a LEGO ID and subscribe to the mailing list using a landing page like this one for the USA. This offer is unfortunately only valid for certain countries (We spotted USA, UK, France Australia and others) but if you are not in the applicable countries (we are not too!), fret not, you can still download a PDF version of the magazine for your kids.
Here is the link to the latest version as well as page to go to when Nov 2019 rolls along (the next scheduled release date)
Here are some screenshots of the latest magazine for July to Sep 2019.