Hi Daniel,
You can check out this document which is pretty thorough:
http://www.cisco.com/en/US/docs/voice_ip_comm/cucme/pbx/interop/notes/410364av.pdf
Otherwise, doing a cisco.com search for 'avaya qsig' brings up a number of other interoperability documents you can take a look at.
QSIG will only be supported with MGCP, so some of the configuration will be specific to your CUCM version.
hth,
nick