In addition to this reference documentation, there exist a number of other resources that may help you learn about AMQP.
For those who are not familiar with AMQP, the specification is actually quite readable. It is of course the authoritative source of information, and the Spring AMQP code should be very easy to understand for anyone who is familiar with the spec. Our current implementation of the RabbitMQ support is based on their 2.8.x version, and it officially supports AMQP 0.8 and 0.9.1. We recommend reading the 0.9.1 document.
There are many great articles, presentations, and blogs available on the RabbitMQ Getting Started page. Since that is currently the only supported implementation for Spring AMQP, we also recommend that as a general starting point for all broker-related concerns.