Macmillan English have collaborated with NILE to deliver a dedicated training programme through an online hub, to get all teachers up to a speedy start with online teaching. This is a very thorough hub, including webinars, videos and instructional blog posts.
Flipgrid is a quick (and completely free) way to send and receive videos to your students. It allows you to make very short videos and students to make short videos in reply.
Learning how to make a course
Take Your Teaching Online is a free self-paced course – you can take as much time as you like to work through the units. The course has been developed generously and very quickly by NILE Online to help teachers at this time. I run one of my courses with NILE and can highly recommend them. The course takes you through several tools that you can use and will enable you to run your own online courses.
For my own online courses, I use teachable.com which allows me to create units including videos, PDFs and other files. It allows students to comment and reply to each other. There are several other systems like this out there. They do charge a monthly fee. I use a dropbox link for students to upload files and assignments.