There’s an amazing amount of couseware and training available on the net nowadays, and colleges and universities are making much of it available free of charge in online format.
Here’s an extensive video course on public speaking / making effective presentations by St. Petersburg College. Here’s a quick description:
SPC 1060 PUBLIC SPEAKING
This course offers practical experience in a variety of forms of public speaking, with the focus on development of personal communications skills and personal effectiveness with audiences. The course will evaluate the principles of speaking and listening using techniques including rhetorical criticism. SPEAKING WITH CONFIDENCE LESSONS 1 thru 24.
The entire course is about 12 hours long, but it’s broken up into 30 minute segments. This is great for beginners or even established public speakers who would like a refresher course.
For more complete information go here to see the content of the public speaking course.