Jacob Sebastian is a SQL Server XML Guru!
Check out his collection for XQUery Labs. This is the first 12 of his series, and right now he has 43 and counting:
XQuery Sample Scripts
* XQuery Lab 1 – Transforming rows to columns
* XQuery Lab 2 – An example using OUTER APPLY
* XQuery Lab 3 – Filtering specific nodes
* XQuery Lab 4 – Joining XML Nodes with a Relational Table
* XQuery Lab 5 – Working with Namespaces
* XQuery Lab 6 – Processing Header-Detail information
* XQuery Lab 7 – Extracting a comma separated list of values
* XQuery Lab 8 – How to update the attribute value of an XML variable?
* XQuery Lab 9 – How to delete an attribute from an XML variable?
* XQuery Lab 10 – How to insert an attribute to an XML variable
* XQuery Lab 11 – How to insert an element to an XML variable
* XQuery Lab 12 – Different ways of reading values from an XML variable
Jacob Sebastian has also released a free ebook via RedGate – The Art of XSD – SQL Server XML Schema Collections
Check it out, all 483 pages!