While you are researching your speech and thinking about your audience, make sure to keep full bibliographic records for all your sources. You should be able to cite all of the ideas, claims, and evidence that you acquired from other sources aloud during your speech. Even if your professor does not require it, doing so will build your credibility and maintain your academic integrity.
Tell the audience your source before you use the information (the opposite of in-text citations). Check out our Oral Source Citation Guidelines (PDF) for more information and Nic Marks's TED talk where he not only cites his sources, he offers ideas for a happier future.