The subject of service virtualisation can seem a little bewildering when you first approach it. I find a couple of simple demos, or walked-through examples, can help to clear through the hype of a dozen high-level articles on a subject. With that in mind I've put together a selection of short, worked examples to gently guide you into the world of Rational Integration Tester (RIT), Rational Test Control Panel (RTCP), proxies, agents. etc...
Rational Integration Tester - First steps starts with basic RIT functionality, through to simple service modelling, service virtualisation and more advanced subjects such as sift-and-pass-through. It also refers to a GitHub project, recently made available by the RIT development team, containing demo material. the demo material in a bit more detail. The material includes pre-built RIT projects and a sample calculator application.
Hope you find these resources useful !
P.S. You can raise problems/suggestions for more examples via the GitHub issues page.