What would be a good place to go to understand arrows? Ideally, I am just looking for some place with a concise definition with motivation from some good examples, something similar to Wadler's exposition on monads.
I found Hughes' original paper ("Generalizing Monads to Arrows") to be fairly accessible. You can read an older draft of it here. It has some differences from the original paper, which are noted on the bibliography page of Ross Patterson's own overview of Arrows.