When you are looking for two services to communicate to each other - what are you looking for exactly? I'd start with p 140 of the ESB Beginner's Guide and read about routers/notifiers and also p.108-112 to read about the ServiceInvoker. There's plenty of quickstarts in this area, depending on how you want the services to communicate.
I'm not sure load balancing is covered in the quickstarts, but it's covered on p.213 of the Beginner's Guide, and you would also want to read the ESB Registry guide (part of the ESB documentation).
Thank you for the quick reply Tom. I managed to get through the helloworld quickstart not using the JBDS, which I think fullfills the first scenario. I'll take a look those pages. I'm starting from the beginning of the book because the ESB wasn't recognized in the admin-console or the JBDS.