People often ask me how to become a public speaker. The first step is to hone your skills and comfort getting in front of a live audience. Second is to know your subject well. Speaking is about educating. The best speakers educate their audience. I could write an entire posting just on these first two items alone.
Once you are comfortable with the delivery and subject, there are five stages to public speaking. Each stage represents increasing levels of expertise, knowledge, respect, awareness and ultimately value to the audience.