After that graphs and plots of data. Albertson Chris, you should not overwhelm yourself with such a broad adjenda. I've also arranged for or given public programs for these clubs. What an astronomy club is looking for in a talk is either some good details into a particular area or topic, OR a good general discussion geared for the general public. Even so, any talk for an amateur club should offer a general introduction, then dip into the details.
CHarts are OK, as long as the subject of the chart is clear.
So touch opon the areas I mentioned if you can. Even if the focus is technical, they will get the general idea from the introduction. And allow for some questions at the end. I think you could put together a good talk just with your own experiences, some material from the Web pages of our colleagues, and our TASS Web page. You probably have all the resources you need already in hand.