Publisher Westminster John Knox
A great resource. Brevity, insight, relevance, and scholarship in one place. May not satisfy some more conservative folks (understands Jonah as more didactic than historical) but I certainly recommend it.
This is the best short commentary you can get on Jonah. It covers all the interpretive issues with skill and care. He also has a great section on the use of Jonah in Christian art. There's a section on Jonah in other religious traditions such as Islam too. In my opinion, you can't get a better brief commentary on this wonderful little book.