I tend to follow the blog I'm pulling the following information from. This blog is based on the idea that all people should be able to perform basic maintenance on themselves. The author posts different "issues" each day and then tells the reader how to fix the issue using stretching sometimes combined with items you can find around any home.
The author of the blog is a physical therapist, so I take what he has to say seriously, and can tell you that I've used his techniques to perform my own maintenance for almost a year. In that time I've encountered a shoulder injury and have been able to remain out of the chiropractor's office despite chronic back issues.
I enjoy this blog because while serious, the author is able to infuse humor to keep it interesting.
Today he's talking about the shoulder issues that we've all likely experienced as runners.