Barnabas, Son of Encouragement

In Acts 4:36 we are introduced to a man named Joseph, but who was called “Barnabas” by the Apostles. This affectional nick-name means ‘son of encouragement’, but did “Barnabas” live up to his nickname?

What do the Scriptures tell us about him?
Who did he help?
Who did he encourage?

But why on earth did he fall out with the Apostle Paul, and were they ever reconciled?