The Art of Public Speaking - The Original Classic Edition

It approaches public speaking from the absolute best perspective: its not about you, its about THE MESSAGE!

AoPS also has amazing introductory piece on being courageous.

One major caveat to keep in mind: The style of public speaking has changed in the past +100 years. Gone are the days of three-hour booming oratories by Webster and Beecher. In their stead modern speaking have to be quick-hitting with profound and engaging stories.

The language is a bit dated, but the content is still relevant.

If you need to do any type of public speaking, networking and small talk, pick up this book right away and start skimming.