Knowing what p values tell us can be tricky to teach. Here are several videos that help explain exactly what p-values are (and aren’t) able to tell us. Each video essentially covers the same content so which one you use can be a matter of personal preference.
A chapter by Beth Chance and Allan Rossman that introduces several key topics in statistics such as: distributions, p-values, confidence intervals, samples/populations, and drawing statistical conclusions . This chapter could serve as an introduction to the topic or as a refresher for students in a more advanced course. You can access the full chapter here.
A really well done video that clearly explains the basics of hypothesis testing. Students could easily watch this at home as part of a flipped classroom approach and come to class with a solid foundation. It has over 2 million views for a reason. This video is from the http://www.MathTutorDVD.com series.