I have taught grades K-5, high school, future teachers, and working teachers, but I have never taught middle school, except for a couple of summer jobs some years ago. Nevertheless, my curriculum materials are widely used at that level, and maybe half the teachers I have worked with are middle school teachers.
I just started a new page on my site, specially intended for middle school teachers. On it, I will post lessons that I have written or adapted for grades 7-8, consistent with the relevant Common Core standards. The page will continue to grow at least until the end of the school year. Much of it (but not all) will be based on material available elsewhere on my site, possibly edited and with additional teacher notes.
–Henri
Henri's Math Education Blog 