The official Petals documentation is available at http://doc.petalslink.com. You can access it anytime thanks to the navigation bar located on top of the page (common through all the Petals websites).
Tutorials and Training
If you want to get a quick start on Petals and are on the self-learning side, we propose a quick-start tutorial to grasp the basics concepts and use of Petals ESB, based on Petals ESB 3.1: get started on Petals ESB in five lessons.
Whitepapers and News
If you want to learn more about SOA and ESB, we recommend browsing these sources: