This book/lesson material is free to use and share unmodified.
The aim is to explain, as simply as possible, the most common design patterns I have used. All examples are represented in the C# language, but the concepts discussed (the crucial parts) extend to any language.
The book is structured as lessons you can take in sequential order: progressing from simpler to more complex/derivative patterns.
Or it can be used as an ad hoc reference, with a handy table of contents and cheatsheet.
Below is a list of the patterns and sections included:
Introduction
Singleton
Prototype
Factory Method
Abstract Factory
Structural Wrappers
Adapter
Bridge
Proxy
Facade
Decorator
Composite
Template Method
State
Strategy
Observer
Command
Iterator
CheatSheet