In Franklin Metro Utility, through an underwater section of the subway tunnels near a lot of radiation. On a shelf with missles and darts, etc. Can also be reached from the subway entrance next to Hubris Comics.
In an ammunition container in the burned out bus near the red railroad car NW of the building that is north of the office (not the same red car where Dogmeat is found). You can get the key from the random encounter "More Than Just Scrap", or you can just pick the lock (hard).
It is likely that "recipes" is an analogy to combat tactics involving the flamer, presented in a humorous format of a cookbook.
This is the only skill book unique to Fallout 3, as it is not present in earlier games and does not return in Fallout: New Vegas, due to the Big Guns skill being collapsed into Guns, Energy weapons and Explosives, as well as being replaced by Survival. Nonetheless, the item itself is still present in the resources of Fallout: New Vegas, but is not placed anywhere in game.
This book is a reference to The Anarchist Cookbook which was first published in 1971, is a book that contains instructions for the manufacture of explosives, rudimentary telecommunications phreaking devices, and other items. It was written by William Powell to protest United States involvement in the Vietnam War.