LiveLingua: FSI Language Courses
The FSI is a department of the Federal Government that provides training for employees of the U.S. foreign affairs and their families. It’s aimed at getting their staff up to an exceptional level for living or working in foreign lands. Much of their content is dated and does have the occasional military term in there but it’s still arguably one of the best free resources available. There are many many hours of free audio available with PDF guides / ebooks.
I like the format of the Live Lingua site, it has the courses well arranged and all files can be downloaded for offline use.