Not sure where to start? Here is a small selection of well-known texts that you should check out first.
Way of the Shadow
New oppers are encouraged to read Psychlonic's night opping guide, Way of the Shadow. It is widely known and respected amongst more experienced oppers for its thorough coverage of fundamental techniques. It also includes several stories which are used as examples demonstrating both effective and ineffective techniques.
Car Shop Op (Video)
Choice example of an actual Night Op.
Stealth Movement Compendium
Several short texts on the art of silent movement.
The MIT Lockpicking Guide
By: Ted T. Tool
The famous lockpicking manual. With a (formerly) locked door, a new world opens.
Modern High Security Locks: How To Open Them
By: Steve Hampton
If the MIT guide is an introduction, this book is the advanced course. Covers lock varieties that offer more complex challenges than those covered in the MIT guide.
Stealth Movement (Video)
By: Robert Bussey
Sometimes it's easier to learn by seeing how it's done - this video is a great example of stealth movement, with some good tips from the narrator.