Links:

MQ official sites:

MQ support
MQ fixes
MQ support packs
WebSphere MQ 6 Information Center
WebSphere MQ 6 documentation library
996 Solution Designer peraratory documents
WebSphere Business Modeler certification prep series

And here are some interesting support packs:

WebSphere MQ Events and Statistics Plug-in - MS0P


Other resources:

Harslay MQ blog - super
IBM Developer Works
Red Books


Discussion forums:

WMQ newsgroup
mqseries.net
listserv