If you are a teacher of science and you are not a member of the National Science Teachers Association (NSTA) then I would highly recommend joining- lots of good resources. However, even if you are not a member you will still be able to access lots of articles, blog posts, lessons, and more for free.
One great way to check for FREE NSTA resources is through the NSTA Blog. Every month the NSTA Blog lists all of the articles from each of the 4 NSTA journals.. and a few of these are made available FREE.
An example of this is an excellent FREE article from the March 2016 issue of Science Scope (middle school journal) titled What We Call Misconceptions May Be Necessary Stepping-Stones Toward Making Sense of the World
Click HERE to check out the March 2016 NSTA Journals.