If you are not familiar with Apache Camel then check out the FAQ or the Getting Started guide.
If you have more time and a fresh brew of coffee then I encourage you to read a somewhat different tutorial that focus on introducing Camel into an existing project step by step. The tutorial is work in progress, so check it out from time to time. The tutorial is based on a real life use-case.
If you have less time check out the regular tutorial that demonstrates how Camel easily work well together with Spring for message exchanges over JMS.
There's tons of stuff in there. One of the most trivial changes to implement but one of my 'DOH why didn't we do that a long time ago' changes is the new tracer; very handy! Great work camel riders!
Incidentally its interesting to see how popular Camel is getting. For example looking at the Apache mailing list activity at nabble there's currently ActiveMQ in first place, ServiceMix in second and Camel doing a pretty respectable 7th behind Wicket, Maven, Struts and Lucene. Pretty good - particularly as its way above all of the Incubator projects combined (including a fair few that have graduated a while ago :), all Apache Web Services projects combined, Tomcat and Gerornimo etc