I found it interesting to see that Melville isn't totally pro-whaling - there are points in the book where he recognises it as the killing of intelligent and (mostly) harmless creatures. As the book nears its conclusion we see Melville's skill in his portrail of Ahab's insanity - how he sees that the sensible thing to do would be to give up the chase, but feels that he has no choice in the matter.
If you are planning to read this book then you might be tempted to skip some of the chapters on general whale facts. Alternatively, since the chapters are short and their are a lot of them, the almost poetical style of Melville's writing means that it's the sort of book from which you could read a chapter a day aloud .
Note: You can read Moby Dick at http://www.enotes.com/mobydick-text/