Alexandra,
Teaching falls under Category D - Creating New Project Management Knowledge. In particular "Serving as a speaker or instructor for project management related courses and presentations".
PMI says that if you are audited for a PDU claim in this category then they are going to want to see the following:
Copies of publications, sample educational materials or course agenda
So my suggestion for you is as follows:
- Keep copies of all materials and marketing info about the course
- Keep a log file in which you track your time. Both preparation time as well as actual teaching time.
Once the course is over you can go ahead and claim all PDUs at once. You can claim 1 PDU for each hour of preparation and actual teaching.
But keep in mind that there is a maximum of 45 hours that you can claim in total for categories D, E and F combined. So if you already claimed 15 hours for F, then you can only claim 30 for teaching.