My father is Lutheran and I have been praying for his conversion, which he seems to get closer to everyday. He recently asked if there was a patron saint of good deeds. If not, is there a saint that was known for doing many good deeds?
All saints do good deeds; it is one of the ways in which sanctity is measured. I recommend that your father look to his interests and determine if there is a saint who shares them. Since he comes from a Lutheran background, he might consider St. Augustine of Hippo, a Father of the Church who founded several monastic orders, one of which counted Martin Luther as a member before his break with the Church.
Postscript: It occurs to me that your father might also be interested in choosing a saint who stressed the necessity of doing good deeds. If that is the case, he might choose St. James the Less, commonly believed to be the author of the Epistle of James.