I work for a large international company > 20K employees, but in this case size should not matter. During an opening meeting my experience is that auditees usually want to know the following:
Scope of the audit: What processes are going to be audited and what are they being audited to (what standard). Some even want to see the checklist which we share with them openly. They also want to know if they need to prepare anything...I usually tell them to have people present that can: describe the process, people that review and improve the process, people that control the documentation and records for the process, people that actually perform the process day to day.
Agenda: Times, places, dates and people who need to be involved in the audit. (To be reviewed and confirmed by the auditee). When will the closing meeting be?
Closing meeting/After the Audit: When will they get the "final draft" of the audit report. Verify the report distribution list. What is the expectation (what should they do) if a corrective action is written. How many days do they have to respond, how many days do they have to fix it, when does that clock start ticking? When will they next be audited by an external auditor? When is there next internal audit.
...those are some of the things off the top of my head
