The U.S. Soccer’s Coaching Education Department has published a coaching guide aimed at establishing best practices for coaching soccer in the United States. Click on the link below to download it:
MYSA lesson plans - Downloadable pdf lesson plans on many topics for different ages. Most specify the age appropriateness
Fine Soccer.com - A terrific archive of lesson plan ideas. However most are single drills with no diagrams. They have some terrific keeper drills in the list.
Footy 4 Kids - A U.K. site with one of the most complete slate of full session lesson plans, plus ideas for working with parents as well as guidelines for the ages you are working with. This site shines for ages U-5 to U-12. A complete soccer coaching web site. Great links page also!
U.S. Soccer Players - This is the coaches resource area
Soccer Fitness - Some great ideas for older player when fitness becomes critical.
World Class Coaching - World Class Coaching puts together a terrific newsletter with drills used by the pros and high level teams around the world. But they also have a coaches forum where there is a chance to ask questions and get answers. It seems coaches of all ages and abilities post here. It's free!