As being the embedded option of Oracle relational database engine, OWB is still my favourite ETL (or to correct ELT) tool. In addition, although Oracle positions ODI as their strategic tool for this purpose, they still keep investing on OWB at least in 11g Release 2.
I have recently had the chance to review a new book by Packt Publishing, namely Oracle Warehouse Builder 11gR2: Getting Started 2011. Book is a good introductory book for newbies willingness to learn more on OWB by playing with it in a playground.
Book is organised to let you build your own OWB environment and work on a toy problem namely ACME Toy and Gizmos. You design and create your source and target structures and implement you ELT.
The book will help those who wish to learn more on OWB and look for a practical guide.