The reason I talked about current information and personal life events first is that they will glean you the highest amount of impact. Using your own life incidents and observations makes you unique. Why should you be asked to speak if anyone could get up in front of the group and recite the same old tired information and stories? I encourage you to spice up your presentations with your interpretations of news events and information and your personal experience.
However, I go back again to the idea that you must change up. An entire presentation based on you could be considered self-aggrandizing and boring. It is perfectly acceptable and needed to include observations and humor of others to support your points. This information is easily found in reference material for speakers. Many reference books for speakers include both serious and humorous material. Here are just a few of the ones I rely on when preparing a presentation. Note: Some may be out of print, but you can search used book stores and use used book search services to find them.
The Book of Business Anecdotes by Peter Hay (New
York: Facts on File, 1988).
Speakers Library of Business Stories, Anecdotes and
Humor by Joe Griffith, (New York: Prentice Hall,
How to be the Life of the Podium by Sylvia Simmons,
(New York: Amacom, 1992).
Most of these resources are categorized by subject and they put thousands of pieces of material at your fingertips.
I also have a generous supply of used books on many other specific subjects. I really go crazy in the used bookstores and flea markets. For instance, at a yard sale, I found a book of baseball anecdotes that only cost me a quarter. When the time comes that I need a baseball story this book is waiting on my bookshelf to help me hit a home run. (I can't believe I used another dumb joke like that!)