We don't know much about Joseph, but here is some of what we do: His genealogy, such as it is, is in Matthew 1. He was a carpenter, of Davidic lineage and likely from a well-respected family, he was pious, probably significantly older than Mary. Some hold that he was a widower and had sons from a prior marriage, thus the reference to Jesus's brothers not suggesting that Mary eventually had children the normal way (others hold that these were cousins, not brothers, which is a possible reading of the text.) All traditional Christian interpretations hold that the marriage was never consummated. Joseph does not seem to be very well-off (hence the manger) but neither is he destitute, he seems able to move his family about (from Nazareth to Egypt to Galilee) without much difficulty, which would require pack animals, etc. and also he was making enough money to be taxed (if he was a pauper the Roman State would not have bothered.)
He might have had a workshop with a number of people working under him or he might have been a self-employed craftsman, it's not terribly clear. He seemed to be calm, reserved, and have a deep decency about him, as evidenced by his wanting to end things quietly with Mary, rather than humiliate her, before he understood the nature of her pregnancy. He doesn't appear much in the Gospels, however he was clearly involved in Jesus' life and considered his earthly father as later on during Jesus' ministry people who scoff at him mention his being the son of the carpenter. However not much is said about him, probably because the writers want to keep the focus on Jesus and Mary to emphasize the special status of both.
There are post-Biblical traditions about Joseph but the above is about what we have and can all agree on and does give a basic sketch of some of his qualities, and a good set of qualities they are.
The best OT passage implying a Divine messiah is probably Isaiah 9:6-7, "For unto us a child is born, unto us a son is given: and the government shall be upon his shoulder: and his name shall be called Wonderful, Counsellor, The mighty God. The everlasting Father, The Prince of Peace. Of the increase of his government and of peace there will be no end, upon the throne of David, and over his kingdom, to establish it, and to uphold it with justice and with righteousness from this time forth and for evermore. The zeal of the LORD of hosts will do this." Some translate this in various tortured ways ("counsellor [of] the mighty God [who, i.e. God, is] the everlasting Father") but doing so is a big stretch.
Anyway, to break it down: particularly interesting of course is אל גבור, "mighty God" and אבי עד, "eternal Father."
גבור is applied as the adjective "mighty" throughout the OT both to men and to God. From אל derives the plural אלהים, a more commonly used title for God in the OT. (Why is the title usually plural, but singular in this particular case? Is this a hint of the trinity? Or is reading that in a stretch?) Now, אל is occasionally used in curious ways to refer to divine power, to false idols, etc. but here it is in rather stark and plain terms: "the mighty God."
עד, "eternal, everlasting", if I am not mistaken is only used in reference to God in the OT. A particularly interesting verse is is Isaiah 57:15, "thus saith the High and lofty One that inhabiteth eternity, who's name is Holy." In a similar vein, verse 7 as above, "the increase of his government shall have no end [אין־קץ] ... forth and evermore [ועד עולם]." Pedantically, the former phrase means that there is no point in time at which the power of the Messiah shall come to an end, while the latter specifically refers to a more theological concept of Eternity. The word עולם will be familiar to any observant Jew as it is in the preface of many of his prayers addressing God: "Blessed art thou, O Lord our God, King of the Universe, etc." "Universe" here is עולם. We have both a spatial and a temporal sort of all-encompassing vastness described here.
Bottom line, we have four very theological terms here applied to the Messiah.
There are a variety of oblique references in the OT which can be read as supporting a triune God, in addition to the plural אלהים and God using the first person plural when speaking of creation in the first chapter of Genesis (which according to Christian doctrine was accomplished through and with the pre-existing Son, second person of the trinity) but generally using the first person singular when speaking to Israel as God the Father. There are some verses which seem to be rather confusing but are somewhat less so if you see more than one person of the Trinity in them, but I am tired and going to leave it here for now. If you are interested I can pick up on this thread another time.
