Cap 737
www.caa.co.uk/docs/33/CAP737.PDF
Maintainance HF
http://www.caa.co.uk/docs/33/CAP716.PDF
Colorado Firecamp - HFACS, the "Swiss cheese" model, Introduction
www.smartcockpit.com (case studies)
www.ntsb.gov/
ntsb/query.asp (case studies)
Lessons Learned From Transport Airplane Accidents
Key point, even though you are an instructor, you need to LISTEN more than you TALK. The only way to engender cultural change in an organisation or individual is to change mindset; as a CRMI you can only do this by listening to the issues people are encountering regularly on flight operations and relate them to other, serious accidents. This is where personal experience comes in. You need to have the experience to understand what is typical and what is atypical of behavioural and cultural norms. People need to come to understand cultural norms exist, but are not acceptible if outside standards.
It doesnt have to be aviation related. You can do a really good case study into the likes of Challenger or the Herald of Free enterprise as you can Tenerife or kegworth.
Have a good couple of real-world examples to hand to back up slides such as the Iceberg model of reporting, The swiss cheese model and the SHEL(L) model.