I am part of the Mozilla Techspeakers program since different years so I want to share few bits of my experience in this post.
First of all a talk that I did as improvisation 2 years ago in Berlin at our first meetup that explain the program.
Since that a lot of things are changed, the program now has a different onboarding process, is open more to non-mozillians (mozillians are people that contribute to Mozilla) and is more structured.
Also is looking more to people that go to international tech conf that do talks also not about Mozilla stuff.
For me the program was important to level up my skills about public speaking and be able to join conferences where for me was impossible.
As I like to share my knowledge I chosen to write everything I learned during the years to not forget anything with a list of books that I suggest.
In the past was a Google Document but now is like a tiny book and as usual I am open to feedback.
I hope that you can find my writing helpful to improve your skills.