Hi Paul

As Mrugank has rightly pointed out, the topic of Adwords has really been overdone. Most products/videos talk about the same thing.

Rather than creating a how-to Adwords guide (of which there is no shortage already), try something different. Maybe you can create a book like "101 Adword Tips". People love reading tips. If you do it well, elaborating each tip with screen-shots, it would easily be 100+ pages, and you can price it in the range of $47 - $97.

Just a random thought off my head...

-Abhi