One of the members of our Asian regional development team for PASS is Jacob Sebastian. A week or so back he told me he'd written an eBook for the Red-Gate folk on XML Schemas in SQL Server. I downloaded it expecting it to be fifty to a hundred pages. It was 483 pages. What can I say: Jacob is a writing machine. You can download it here:
http://beyondrelational.com/blogs/jacob/archive/2009/04/26/my-latest-book-the-art-of-xsd-sql-server-xml-schema-collections-available-for-free-download.aspx