Jeffry Borror has published q for Mortals Version 3, An Introduction to Q Programming. You can read the first chapter, “Shock and Awe,” at the Kx wiki, code.kx.com.
Also called Q4M3, Borror’s book is a thorough presentation of the q programming language and an introduction to the kdb+ database. It is a complete rewrite of the original Q for Mortals that is current with q3.3.
The presentation is derived from classes taught by the author at international financial institutions over the last decade. It is a series of tutorials based on q snippets intended to be entered interactively into the q console by the reader.
It is available at Amazon and in the United Kingdom, it is available at Amazon UK.