On top of all the excellent recommendations, I always have newbies start with the official IBM MQ Primer - http://www.redbooks.ibm.com/redpapers/pdfs/redp0021.pdf for a mid-level introduction to MQ and messaging.
I hope this helps.
David
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David Awerbuch
MQ admin, MQ developer, MQ firefighter, real firefighter.
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David Awerbuch
Senior Messaging Specialist, Firefighter, all around great guy.
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