Disclaimer: I'm currently enrolled in a Confident Communicator course that Poornima and Karen teach, so I'm obviously a fan of their approach :-)

I've done some public speaking in the past, but this is the first resource I've come across that really guided me through the process of planning, pitching and presenting a talk. The conversational tone of the book makes it an enjoyable read, while the chapter recaps make it a resource I know I'll turn back to again and again over time.