The EduTeX working group coordinates the effort in teaching TeX and using TeX in schools and universities. Our mailing list is email@example.com. Please join us if you are interested in TeX in this environment! You may also be interested in the PDF Accessibility working group, which has considerable overlap; that's the best place to make targeted donations.
Some course materials useful for teachers
Overleaf offers a course by its founder, John Lees-Miller, in three parts:
Overleaf also has a webinar-format intro of LaTeX for biologists: http://bitesizebio.com/webinar/20591/latex-for-biologists/ and three-part introductory series of blog posts (from Arin Basu in New Zealand):
Speaking of Overleaf, here is an example of a project done on this platform in Russian): July Tikhonov taught a 8-hours class for eight-graders using a combination of LaTeX and Asymptote. As he writes,
The plan was to introduce them to an example project with minimal configuration, and explain basics like where are comments and what is preamble and where is the document.
After that, I got them to copy the project and type some problems (taken from their olympiadic math courses, actually) with solutions; since the group was small, I could mentor each of them on using relevant LaTeX constructs, Russian language constructs and style, and Asymptote.
Here are example projects I used (all in Russian):
Part 1: https://www.overleaf.com/read/phsnfnzsbrxh
Part 2: https://www.overleaf.com/read/kvdmrqrntfxn
Here is some of what I got as a result: https://www.overleaf.com/read/vtvtvtcrjntm (the \kratno definition I provided to them)
Another Russian course: Danil Fedorovykh with Higher School of Economics (Moscow, Russia) offers a Russian Introduction to LaTeX at Coursera.
Another Russian course: Eugene Strakhov with Odessa National University (Odessa, Ukraine): course materials.
Petr Olšák teaches a course for beginner (plain) TeX programmers (in Czech). His books TeX pro pragmatiky, TeXbook naruby, and Typografický systém TeX are available in Czech.
The Spoken Tutorial initiative of the Goverment of India offers many multilanguage tutorials on various subjects. They have several introductory LaTeX tutorials in many languages: http://spoken-tutorial.org/tutorial-search/?search_language=&search_foss=LaTeX
UK TUG has run several training courses for beginners, with the loose theme 'Using LaTeX to write a PhD thesis'. The material is available from https://github.com/uktug/latex-beginners-course.
ShareLaTeX offers a number of educational videos in its YouTube channel, https://www.youtube.com/user/ShareLaTeX/videos. Among the introductory ones are:
Overleaf offers a series of 21 introductory LaTeX videos from Vince Knight: https://www.youtube.com/watch?v=4B8Cmm9scmU&list=PL9awiqWAOEaLQ875dCPk0nz7gKv79lTLH
Will Robertson at TUG18 discussed creating teaching material with LaTeXML for the Canvas Learning Management System: Video.
A discussion of learning resources on StackExchange: http://tex.stackexchange.com/questions/11/what-are-good-learning-resources-for-a-latex-beginner