I picked up a book the other day from the American Society Of Safety Engineers called "Guidelines for Hot Work in Confined Spaces".
It's a pretty short book, costs a bunch of money for a short book(could buy 10 Tom Clancy novels) but it is full of good information. I was reading the API 2201 "Safe Hot Tapping" and believe this is where I ran acrossed the info about this book. For me, as a young, well not young but new to this field it was informative as far as the dangers, what to look out for and so on. I'm sure that most places will have a safety person doing such things but in my mind it's nice to know what is going on so at least as the welder, the guy or gal in immediate danger of DEATH if somebody screws up at least I will have a basic understanding and if I don't feel comfortable can ask questions.
Book info,
Guidelines for Hot Work in Confined Spaces- Recommended Practices for Industrial Hygienists and Safety Professionals- Author, Martin H. Finkel, CIH, CMC
One note, it does not include any info about hot tapping, I believe they said you could write to them and they might include in the next edition or something of that nature.
Enjoy,
Shawn