I could write blogs on how to learn the many features involved in working with COBOL, but I thought it would be better to add links here as I come across really good tutorials that are already out there.
As a COBOL coder, you will need to be familiar with a Mainframe environment as well as the tools associated with this environment.
In the modern world, you can look up almost any COBOL coding related topic online. The IBM Redbooks are a reliable source of information for COBOL coders. You can search on various topics such as CICS, JCL, ISPF, DB2, SQL, and many others.
Compuware is a software company that focuses on Mainframe. A search of the products on their site will give you information on such useful COBOL coding tools as Xpediter and File-AID.
GnuCOBOL is a free COBOL compiler that’s easy to download and use.