The New York Times' Jodi Kantor has written a lengthy profile of Barack Obama's time teaching at the University of Chicago:
The young law professor stood apart in too many ways to count. At a school where economic analysis was all the rage, he taught rights, race and gender. Other junior faculty dreamed of tenured positions; he turned them down. While most colleagues published by the pound, he never completed a single work of legal scholarship.
At a formal institution, Barack Obama was a loose presence, joking with students about their romantic prospects, using first names, referring to case law one moment and "The Godfather" the next. He was also an enigmatic one, often leaving fellow faculty members guessing about his precise views.
The Times has also compiled a large set of Obama's old class materials here. Here's a preview from a class reading packet: