Introductory learning materials Start here: Here's What Happens When an 18 Year Old Buys a Mainframe. Great video. https://www.youtube.com/watch?v=45X4VP8CGtk&t=94s z/OS introductory video course http://www.redbooks.ibm.com/redbooks.nsf/redbookabstracts/crse0304.html?Open Master the Mainframe https://www.ibm.com/it-infrastructure/z/education/master-the-mainframe The ABCs of System Programming redbooks http://www.redbooks.ibm.com/abstracts/sg246981.html?Open IBM z/OS Basic Skills page in Knowledge Center.  https://www.ibm.com/support/knowledgecenter/en/zosbasics/com.ibm.zos.zbasics/lcmain.html Introduction to the new mainframe http://www.redbooks.ibm.com/abstracts/sg246366.html?Open Introduction to CICS http://www.redbooks.ibm.com/abstracts/crse0303.html?Open Db2 DB2 for z/OS: Data Sharing in a Nutshell Mq on z/os concepts https://www.ibm.com/support/knowledgecenter/en/SSFKSJ_8.0.0/com.ibm.mq.pro.doc/q003590_.htm http://share.confex.com/data/handout/share/131/Session_23611_handout_11867_0.pdf RelevantZ site http://relevantz.ibmsystemsmag.com/ibm-systems-relevant-z IBM Z Youtube IBM Z YouTube channel Introduction to CICS from IBM http://www.redbooks.ibm.com/redbooks.nsf/redbookabstracts/crse0303.html?Open Introduction to the (new) mainframe) http://www.redbooks.ibm.com/abstracts/sg246366.html?Open Books (search for 2nd hand versions) Teach Yourself COBOL In 21 Days Murarch’s Mainframe COBOL Assembler training Assembler training IBM System z Tech IBM System z tech zone Love mainframe site https://lovemainframe.com/ Relevant Z http://relevantz.ibmsystemsmag.com/ Zowe https://www.openmainframeproject.org/ Free training offers IBM z/OS Introduction and Workshop for the IT Professional - 5 Day Edition (Next Offering: November 11th to 15th - USA CDT) https://www-01.ibm.com/events/wwe/ast/mtm/zlearn.nsf/enrollall?openform Free training at HPI https://open.hpi.de/courses/mainframes2018 Many tutorials on Mainframetechhelp https://www.mainframestechhelp.com/ Tutorialspoint on mainframe https://www.tutorialspoint.com/mainframe_tutorials.htm Mainframe Playground  https://mainframeplayground.neocities.org/ JCL course https://www.tutorialspoint.com/jcl/jcl_job_statement.htm Free COBOL course from CSIS http://www.csis.ul.ie/cobol/course/ z/OS Introduction and Workshop http://dtsc.dfw.ibm.com/MVSDS/'HTTPD2.APPS.ZOSCLASS.SHTML(ZOSCLASS)' Mainframe playground on COBOL https://mainframeplayground.neocities.org/COBOL.html Access to real mainframe Community mainframe Unfortunately there is no Community open source mainframe yet. How cool would that be - a z/OS system on real Z hardware not owned by our boss. zD&T There is the emulator solution zD&T on which you can run z/OS legitimately. If you can afford it and like tinkering with an Intel machine an dLinux. IBM Z trials - only 3 days https://www.ibm.com/it-infrastructure/z/resources/trial Only available for 3 days Master the mainframe - free https://www.ibm.com/it-infrastructure/z/education/master-the-mainframe Remote development programme on Dallas System z When you have a software development company, or if you are rich. http://dtsc.dfw.ibm.com/MVSDS/'HTTPD2.ENROL.PUBLIC.SHTML(ZOSRDP)' Will start at something like $550 USD per month.