PowerPoint presentations can be extremely useful in the classroom to help introduce a lesson and to help students understand the concepts being taught. Below is a list of sites that offer already made PPT presentations for teachers. Some can be modified, others cannot. Besides the list below, a good way to search for a PPT with Google is to simply put in the topic name followed by filetype ppt. For example a search for Civil War PPTs would look like: "Civil War" filetype ppt.