The books of Samuel are part of what is now called the "Deuteronomic history" (Joshua, Judges, 1 and 2 Samuel and 1 and 2 Kings) which was written by an anonymous author, now known as the...
Overall, the book of Acts is talking about the preaching work, or ministry work of Peter and Paul (who's name used to be Saul before he became a believer of Christ).
It's talking about how the...