Nice inquiry, Sarah. I've actually given this a lot of thought in recent months as I expect to have just such an opportunity in the near future. I've done a lot of professional presentations through the years, as well as teaching for work and church. I always start with a few general thoughts:
- What do I think the audience already knows?
- What do they want to learn?
- What concerns do they have about the subject?
- What can I share with them that will best address their concerns?
- What do I want them to take away from the discussion?

There's a lot of variation in the public in information and disinformation about crossdressers, so it'll be hard to cover as much as you'd like if you only have a few minutes or even an hour. If you're dealing with a subject that most of the audience fears, it's generally best to assume they have little or no solid information and start by addressing the concerns, then moving on to deeper material as time allows.

Given all that, I'd suggest the following as a starter:
- We're just normal people. In fact, they probably know a number of crossdressers but don't know which of their contacts are CDs - just as they don't know which of those contacts experience any of the many wonderful varieties in life.
- I'm just one example of a crossdresser, and there are many different variations from those who crossdress just a little at home to those who crossdress nearly full-time (you can expand on this if you like).
- We're often considered to be part of the transgendered world, which introduces even more variations, including full FTM or MTF transsexuals.
- Some crossdressers are homosexual, but most are straight - just as it is among non-crossdressers.
- Many of us try to emulate the best qualities of the women we've known in our lives.
- None of us can really tell you why we crossdress, but we can share how we feel when we do.

I think you can see the general sense of what I'm relating here, and others can expand on it. If all this goes well and you have more time, you can delve into trickier subjects. But it's easy to overwhelm people the first time out so be careful.

Good luck.

Mir