Because there are many branches of Buddhism (and multiple contradictory teachings within), it’s tricky to nail down what we might call Buddhism 101. But that’s sorta what you’ve got with the 2-page handout offered here, “Buddhism Basics,” which you can print and use with your small group.
The concise chart and the breakdown by numbers (4 noble truths, 5 precepts, 108 sins…) provide a simple starting point for your own further research.