There are so many fantastic courses, learning paths and materials available on the Microsoft Educator Centre. Any teacher can benefit from signing up and trying their courses. It's easier than you think. Select a course, go through the material and do a short quiz afterwards. You can earn badges (I'm not a 'badge' person myself but I recognise the value of rewarding learners) and also have access to a complete transcript to all the courses you have completed for your own records or CV. It's great for professional and personal development.
I have put together a list of 24 course I think are pretty useful for teachers to look at - that's 2 courses a month. Now, the word "course" sounds daunting but they courses are mostly 1 hour in length. So, if you can put aside about 2 hours in a whole month, you can do up to 24 courses in a year! That's pretty impressive, I think.
An alternative to doing a course, is to choose a Learning path. A learning path consists of an overall theme with various courses you complete covering that theme. A learning path is recommended if you would like more well-rounded experience and exposure to a greater range of teaching tools and concepts.
I have made the document available as a PDF or an editable Excel file for everyone. Enjoy