I got more than I expected from "OS/390 and z/OS JCL". Not only were the chapters on JCL itself very clear and complete, but this was really a collection of small reference books. For example, there is a section on IDCAMS, which is going to be very useful, because it has all those parameters that I can never remember. There's another section on batch utilities, which shows you how to use them with HFS directories. I would very much recommend this book to anyone new to z/OS -- or anyone like myself who gets annoyed at how difficult it is to find out some detail that they have just forgotten.