The scriptures say little about him. We know him to have been "a just man," who when learning that Mary was with child during their betrothal, was prepared to divorce her rather than have her punished for adultery by stoning. But an angel came in a dream and set him straight. Catholics believe that "he did not know her until she bore her firstborn son," but the word "until" in this context does not imply that they consummated their union afterwords, thus Mary retained her perpetual virginity, and they essentially "lived as brother and sister." The last we hear of him was when Jesus was twelve, and Joseph and Mary found Him in the Temple after thinking He was lost.
An ancient legend says that Joseph was an old man of ninety years when he married Mary. She was likely only sixteen, maybe even fourteen, which would not have been unusual for the time. Another legend says that Joseph was a widower when he married Mary, and that he had four sons and two daughters from the previous union, one of those sons later becoming an apostle, "James the brother of Jesus." While upheld as a pious tradition by Orthodox Christians (who remember Joseph on the Sunday within the octave of Christmas), James was most likely a cousin of Jesus, such distinctions within a household being uncommon back then.
Joseph was a carpenter in Nazareth, a remote village (what we would call a "hicktown" today) in Galilee. There is some indication that Jesus learned His father's trade. It is likely that Joseph died at some point during Jesus' early adulthood, leaving Him to take over His father's trade, and care for His mother alone until He began his public ministry at thirty years of age.