John Piper says that his first encounter with John Calvin was through this short biography, called Portrait Of Calvin by T.H.L. Parker. Hearing that made me want to pick this book up.
I will say first of all that John Calvin was not what I had expected. Because of "Calvinism" he has been portrayed as this cold, unfeeling, almost dictatorial leader. Reality though, none of those is true. He was actually a very warm, tender individual. He showed great care and concern for the people he was pastoring.
Though there was political influence that he showed, the reality is that he was simply a pastor. He preached the word of God and he did that consistently. Throughout his life he would preach in an expository fashion through books of the Bible. Whether it be Old Testament or New Testament, he plodded his way through passage after passage, making the central theme of his preaching Christ and the core of that preaching focused on the passage.
If you would like a taste of who John Calvin was, not simply as the historical figure that you've heard about, but a closer examination of his life and ministry, then I would like to highly recommend this book. You can get a hard copy through Amazon, but the Desiring God website has a free ebook (that's where I picked it up).
If you read it, let me know what you think.