Right now I’m reading a book called Twenty Master Plots and How to Build Them. It’s a really interesting look at plot, and at commonalities in plotting. Now, unlike a lot of books, this one doesn’t say “There are only twenty plots in the world”, instead it says “Here are twenty plots that you can work with. There are probably more we missed, maybe a lot more.”
Anyway, it’s a good book and a good read. The initial chapters are an exploration of what plot is or is not and are entertaining. After that, it gets into the plots themselves and explores them at length. Give it a read, it’s great stuff.