[Discere]

If there is a local Toastmaster's club I would recommend going: http://www.toastmasters.org/ there are other clubs but they provide a very supportive environment for starting to speak in public.

I've been lucky enough to speak at a few conferences, and if you're confident on your subject, which I am sure you are, you should just think of it as you passing on your experience. Don't think of it as a judgement of you or your past, people there want you to do well, you're up there for a reason which is because you're the one who can give them the information they're there to hear.

I say go for it, if you can go to a speaking club near by to get constructive criticism and help your confidence

Good luck!