This document outlines the academic integrity policy for the Communication Department.
You must cite your sources in your speech and if required, create a bibliography page to give credit to other folks. I know this sounds stupid but how would you feel if someone stole one of your ideas and made a fortune off of it. I realize you are not going to make a fortune from your speech but it will definitely lend to your credibility if you tell your audience where your information came from.
Make your professor happy and tell where your information came from even if it is from the web!
For examples: check out http://libguides.lamar.edu/MLA
see the Works Cited tabs for examples
Another great place to go for help with MLA: https://owl.english.purdue.edu/owl/resource/747/01
Citing Sources in a Speech from the University of Southern Mississippi Speaking Center
Citing Sources within your Speech from Bucks County Community College
Citing Sources in Your Speech from Central Michigan University