Informative Speech Topics
You should think about your own interests, hobbies, family, friends, activities, etc. for inspiration. If you choose something you really like, your speech will be much more interesting.
Any current event may be an opportunity to inform an audience. Also, an interesting hobby might make for a good topic for an informal informative speech. The most important thing is to know your audience, and speak on subjects they will find interesting. For example, a group of intellectuals may not find a speech about how to build a doghouse that interesting.
(For other ideas, see the related link.)