One option when finding images is to look for creative commons or public domain images. The following sources are great places to do that. Creative Commons images require an attribution message, so be sure to cite your source.
This site has five different graphs and charts you can customize for your speeches. Once you choose a graph, you set the design, input the data, and add labels. Graphs can be printed, downloaded/saved, or emailed.
This video shows you how to embed YouTube videos into Microsoft PowerPoint 2013.