Do u want to learn SKILL or OCEAN?
In case u want to learn OCEAN, there is very nice site as a beginning which is easier and more interesting than the references, check it below **broken link removed**
I would suggest taking the SKILL Language Class at a Cadence location. It's usually about 5 days long and is very helpful especially for a beginner. You learn about the syntax and how to create menus, read and write from files, etc. The class is split up between lectures and labs so you get hands on experience. Go to www.cadence.com and click on Support->Education. You can also search the web for example SKILL files. I believe the file extension is ".il" for these types of files.