Useful mostly for beginners in the wonderful world of small arms, Guns and Bullets permanently improves the Small Guns skill level. However, reading alone will not make a marksman; the higher the reader's skill in Small Guns, the smaller the skill increase will be. At very high levels, the magazine will do nothing at all. Specifically, once the skill reaches 92%, the book will do nothing (this applies to all skill books in Fallout and Fallout 2). It is however possible to adjust this through the difficulty setting, or by temporarily lowering your SPECIAL attributes (and the corresponding skills) through drug use.
In the left-hand room second from the bottom, on the upper right hand shelves. Use alcohol to lower the bald thug's perception by 9, then use Sneak to get the book.