Do you have access to the Training materials for Rational Robot? There are some good posts on Developer's Works (IBM) for the tool. Bring you up to speed pretty quickly with it.
Robot isn't a tough tool to learn. The script language is VBA, the IDE is straightforward, objects are recorded in-line as the Recognition Methods, Verification/Checkpoints are straightforward, and working with data files is easy.
If you're working with web-based apps the function library is pretty good. You will be limited with some technologies, but because of VBA you do have some extensibility. You can write your own functions and include them with the script(s). Again, via VBA and Windows Scripting Host (WSH) and calling COM objects you can extend the tool.
The classroom training is typically done by IBM or a partner. Otherwise you will need to learn on your own.