Discuss the difficult questions of life that are addressed in job? what aspects of god's character are challenged by the presence of evil in the world? how are the difficulties resolved?

Job is an immensely complicated book to read, especially for a modern reader. It is almost as though Satan is challenging God and getting the better of the "discussion." (Read that to mean argument). 

The main arguments are between God and Satan.
Between Job and his "comforters."
Between Job and God
Between The world at large, where Job represents every man (and woman), and the evil that is in the world.  

The main thing that is challenged with God is his right to rule and the things that man does that displeases him.

More over Satan thinks that every man has his price, and every man can be broken. God thinks differently. 

The difficulties are resolved by God's insistence that he is the monarch of the universe. He created it from the thoughts in his imagination. He points this out to Job. The result is that Job endures and Job's righteousness prevails and God rewards him as he rewards everyone who prevails by giving them the wisdom to understand what they are going through or have gone through.