Flexibility Should Be The Name Of Your Game by Greg Siller (Pro Learning Systems). This site talks about the two types of stretching, the six areas you need to stretch properly, gives pointers on stretching, and concludes with a 14-minute stretching program for hockey goaltenders.
How to Stretch by Brad Appleton. This is just a small chapter in a very large website, titled "Stretching and Flexibility: Everything You Never Wanted to Know", which is, in itself, worthwhile to peruse. This particular chapter talks about how to stretch (duh), including when and in what order to stretch. There's even a paragraph on "doing the splits" (a particular favourite for goalies).
Improving Flexibility Through Stretching, by SpineUniverse.com. Just the basics here, with a list of different stretches accompanied by illustrations. A quick and dirty set of twelve stretches, from the shoulders down to the calves.