Design pattern reading:

Design pattern intro: http://www.developer.com/java/other/article.php/3325211/What-Are-Design-Patterns.htm

factory pattern example: http://www.tutorialspoint.com/design_pattern/factory_pattern.htm

factory pattern details:

http://www.oodesign.com/factory-pattern.html

factory tutorial: http://www.newthinktank.com/videos/design-patterns-tutorial/