Clytie,
Also, make sure that you do your homework before you step into that dismissal meeting. You are delivering the facts in terms of the need to go your separate ways, so have the facts straight and plan for the delivery. The professional and calm delivery that you mention is key to getting the job done appropriately. I always try to have HR in the meeting as well. They can take over on the process of separation--COBRA, severance, collecting keys and equipment, etc.
Pat
