It is part two, dealing with St. Francis of Assisi that is truly wonderful. Get to know this lovely saint, this man of Christ via this mini-documentary. You can do no better in English than Donald Spoleto's biography, Reluctant Saint: The Life of Francis of Assisi.
For a truly San Franciscan treat, watch in succession Francesco, starring, not as improbably as you might think, Mickey Rourke as St. Francesco and Helena Bonham Carter as St. Chiara, filmed in 1989, and directed by Liliana Cavani. Then, watch Roberto Rosselini's The Flowers of St. Francis, which stars real-life Franciscan friars. I have to admit, but not snobbishly, that my least favorite film about St. Francis is Brother Sun, Sister Moon.