Hello World – A magazine for teachers and kids about making and computing. Free to download, also free by mail to UK educators.
Make Magazine – A print and online magazine for inventors and tinkerers of all ages.
HackSpace Magazine – Although published in partnership with the Raspberry Pi Foundation, this magazine offers open source projects for a wide variety of physical computing and fabrication projects. All issues can be downloaded for free.
Popular Science – Magazine and website has DIY projects, science and technology news, and reviews on gadgets and computers.
Popular Mechanics – Published since 1902, this magazine and website is best known for automotive and home projects, but often runs science and DIY articles and projects.