Look at your base metal information, that is what the need for preheat, interpass and PWHT derives from. Most of the time the weld will pretty much take care of itself provided filler selection is correct and the welder knows what he is doing. It is the effect of the process on the base metal and heat affected zone that is of the most concern. In addition to the references I mentioned earlier, get yourself a copy of the AWS Welding Handbook and the ASM Welding, Brazing and Soldering Handbook. When other sources fail to give you the information you need, these publications will usually get you in the ballpark based on both the science behind welding and the practical experience of people finding out that science isn't always 100% correct. Knowing where to look is more important than just knowing it, memory fails at times, trust me on that. I tend to believe anything relating to metallurgy is 50% science and 50% black magic, or so it seems at times. As for 40+ years, most days I wonder what I was thinking way back when, even though it has been an interesting journey.