These are some databases to use to start brainstorming or researching about a topic. They will give you an overview of a research topic and some ideas of ways that you can pursue the topic in more detail.
They will also provide multiple points of view that can help with your informative and persuasive speeches.
These databases can work for your Informative AND Persuasive Speeches. Many of these databases contain scholarly, academic or peer-reviewed sources as well as popular sources.