THE WRITING CENTER at the University of North Carolina at Chapel Hill provides a tips and tools resource.
Although designed for the college level, the tips and tools at this website are useful for middle and high school students. The materials are organized into four categories: writing the paper; citation, style, and sentence level concerns; specific writing assignments or contexts; and writing for specific fields. Most of the resources are handouts, but a few involve short YouTube videos.
Librarians will find the handouts and videos useful across many grade levels. Be sure to share the Writing for Specific Fields section with teachers in each content area.
To visit the website, go to https://writingcenter.unc.edu/tips-and-tools/.