Packt Publishing hat recently published a new Book: the "Talend Open Studio Cookbook" by Rick Barton.
As Data Warehouse developer and engineer, I've been extensively used Talend for many years. Apart from the basic tutorials provided by Talend, however, my only source for learning has always been the proactive Talend online community.
This book doesn't digress too much in theory and provides a full, comprehensive view on many every-day, concrete situations and their corresponding solving patterns. The learning-by-doing "recipe" approach followed by the book makes it easier to read and understand it. The book also provides a good foundation of XML principles; unfortunately lacks a chapter about the development of custom components, a scenario that is more likely to occur than expected.
Prerequisites for the book are a basic knowledge of Java or any c-like object-oriented programming language, as well as a rudimentary understanding of relational concepts.
I highly recommend this book for both IT experts and novices with a focus on system and data integration.