What was the nature of the debate between James and Paul?Obviously this question pertains to the Bible. (I don't really need a long answer)
Paul basically states that people are saved by faith alone by the grace of God in Christ. His theology comes out clearly and forcefully in places like Romans 3, Galatians 2 and Philippians 3. You should read these chapters to understand that Paul wants to take out works in salvation. He wants to underline the substitutionary sacrifice of Jesus and hence the grace of God. Work only come to play after salvation.
James, on the other hand, emphasizes the need for works right away. James 2 is a powerful passage that speak of his theology of the need for works in salvation. His pen drips with sarcasim toward the person without works. This is why scholars have seen a debate between James and Paul.
In my opinion, there is no conflict. They are facing different audiences, problems, and hence their theologies have different points of emphasis. The best resolution is to say, "A persons is saved by grace, but that grace which saves, is accompanied by works. In this way, we do justice to both James and Paul.