I'm looking for websites/companies/freelancers that offer affordable or free ready-made materials and resources for an online English practice. These can be grammar and vocabulary exercises, video lessons, pictures and graphics and so on. They need to be released with no copyright or sold as I want to use them in my school's e-learning platform which is commercially distributed. The resources don't have to be prepared for Moodle as I'm able to convert them myself.
I'd be grateful for any links and suggestions.