Try the web sites for the major mfg's of welding equipment. In the U.S. this would be Lincoln Electric, Miller, etc. Most of them have on line FAQ's and literature available. There is a lot of free literature available from the major mfgs also. Check the internet for Mil specs concerning welding, there is a lot of info available from the military, primarily the Navy in the U.S., covers methods, material, equipment, inspection, etc.
johnscrowe@att.net