Biblical Reference on Forgiveness????????????Do you know where any are at?????????????/?

I know that there are references throughout the Bible on forgiveness. I am teaching a youth group lesson on forgiveness and following God. I am trying to make footprints with modern day scenarios about forgiveness that parallel the Bible. I have some verses that I have been studying from 2 Samuel about Saul and David. I was also thinking about the robber on the cross next to Jesus. I'm still studying, but any references would be helpful. IF you just give me the book chapter and verse I will look it up.