Wouldn't the marketing and self-improvement classes negate each other?
The key to self-improvement is broadcasting to everyone that your a better changed person. Better yet, don't change but just do a better job of portraying yourself in a better light.
There are a couple of things on this list that claim to be free, but when you click through aren't. One example is the 10 Days to Better Design course that is actually $10.
Ok, we took "free" out of the title above.
tldr:
> Marketing Courses Reduced To 5sec GIF's: Present your product like Steve Jobs!