Background on Job

Martin Luther called Job "magnificent and sublime... the most beautiful and most difficult" book in the bible.
French Author and Poet Victor Hugo said that "Job is perhaps the greatest masterpiece of the human mind. If it were given to me tomorrow to destroy all books, save one... I would save the book of Job"

Notes from Walter Brueggemann's "Introduction To The Old Testament"

• The story is undated; it "uses older genres and patterns of speech and fashions them into the most artistic and practical statement of faith in the Old Testament."
• "...challenges the basic premises of Israel's faith."
• "...refuses easy resolution..."
• Composed mostly of lament and hymn, which it pursues to an "emotional, artistic, and theological extremity."
• "An immensely sophisticated artistic work that is removed from any particular historical context or crisis."

Notes from Charles Swindoll

• The book of Job is a protest against religion that has been reduced to explanations or pat answers
• You never get over grief completely until you express it fully. Job didn't hold back.

Other Notes:

• The story itself is believed to predate the earliest scriptures. 
• Some scholars believe the opening and closing of the story, which is written in prose form, frames the basic story from the ancient tale. The poetic sections, which comprise the vast majority of the book, were written by unknown author(s), possibly during the time of the Babylonian Exile, although Jewish Rabbinical authorities ascribe authorship to Moses, who they say wrote it to comfort the Israelites when they were enslaved in Egypt. In short, we don't really know.
• In Jewish tradition, Job was an actual, historical man who was a very powerful figure in the ancient world. He is believed to be the son of Uz, who was the son of Nahor, the brother of Abraham. There is also a minority of Rabbinical scholarly opinion that believes that Job was not an actual historical figure. In this view, the book of Job is a morality tale written by a prophet to convey a divine message. 
• The Greek historian Aristeas identifies Job as being "Jobab, the great-grandson of Esau", as mentioned in Genesis 36.
• In Islam, Job is considered to be a historical person and a prophet of Allah. He was struck with all the same tragedies recorded in the Jewish and Christian scriptures, but there is no mention of lengthy theological debates with friends who came to console him. Much of the rest of the story, though is very similar to the Jewish and Christian texts. There is a tomb outside of Salalah, in southern Oman, that local tradition says is the tomb of Job. There are at least two other locations that also claim to be Job's tomb. 

If Job was written, as some scholars claim, during Israel's Babylonian exile, one metaphorical aspect of the story that would not have been lost on its readers of that era is that of Job being an archetypal representative of Israel itself. His ten children directly related to the ten tribes of Israel which were lost, but the restoration of Job's children in the end (or at least getting ten new ones) gave the exiles hope toward restoration and renewal of their country.