OK Guys after reading the responses I am starting to get an idea of what direction I am going to take.
I am thinking I will follow the pyramid approach. The traditional way to write newspaper articles is to give the most important information at the beginning and then work your way back so the last paragraphs of the article give the greatest detail. I can see this working for welding instruction. Each section would give you the basics up front, of say MIG, like how to set the machine and move the gun, and then digress further as you go into it towards WHY you do those things. If you can catch on fast you don't even have to read the whole section to get started.
First I am going to do a general welding book that covers GAS, MIG, TIG, STICK, Fuel-gas cutting, and Plasma cutting.
A second book will cover just TIG with a lot more info on fabrication.
Each book will have a large reference section in the back, or maybe I will have a third reference book, separate from those 2.
As to the DVD/Video tape, I will do one that accompanies each book. The videos will be available by themselves as well, but will work hand in hand with the books.
I wrote a welding book many years ago, but it was specific to the theatre industry. I never got it published, but it taught me a lot about the publishing world. I have an offer from a fellow who runs a printing house to offer print-on-demand services. So there would be no large upfront cost for printing. As each order comes in, the book is printed and sent out. It seems the safest route. There is a shop here in Seattle that does nothing but DVD and CD-ROM production, called Discmaker. They can easily handle mass producing a DVD, once I have the content.
Feel free to keep making your suggestions as to content. I will keep taking notes.