What would be a good recommendation for a practical resources on using xml, xpath and xquery?

By practical I mean.

Accessing values, storing files, creating set queries on xml to create a feed to push data to other applications (eg ipython, rstudio, the Web) maintaining data integrity, and transformng data types.

Note I have completed the W3c tutorials.
Thank you for taking time to help me.

This would mainly depend on which language you intend to use.

A programming language will be the main driver for most of the above tasks and therefore each language will have its own ways of doing them.