Since you are just asking for Bible verses which touch on this topic, there are plenty of concordances and such online that give quotation texts. Two examples of these are in the links below.
There are a few Bible verses on the topic of forgiveness that are really quite well known. For example:
- There is Isaiah 1:18. This is the verse about how our sins will be made as white as snow or as wool even though they are so bad as to be scarlet right now. This is about God forgiving us.
- Even more famous would be the Lord's Prayer (Matthew 6: 5 to 13). There, of course, Jesus tells us that we must pray that our sins be forgiven and that we must also forgive others who sin against us. The two verses right after the Lord's Prayer reinforce this, saying that we must forgive others if we wish to be forgiven.
There are, of course, many other quotes. Follow the link or search Google for concordances or "bible verses by topic" or something like that for more.