I am currently interested in learning more about using Hadoop to create scalable ETL scripts. As part of that, I want to build a solid understanding of data integration best practices, and the challenges of the field. There are a couple of books that I see on Amazon, specifically Data Integration Blueprint and Modeling and Principles of Data Integration, but these books are quite expensive (and the less expensive one seems to have mixed reviews).
Am I overlooking a seminal text on the field? Is there something analogous to Thomas Erl's excellent Service Oriented Architecture books for this area?