I just had a quick crawl round the web to find guides to breakfalling and thought I'd post a few URLs here so that if anyone searches the forum they'll have a few links to hand. Feel free to add any of your own favourites.
An Aikido based site with exercises that supposedly allow you to practice at home. Annoying google ads allover the page but if you cut and paste the text that isnt advertising into a word processor it becomes a decent pamphlet.
Written guide to breakfalls with lots of tips. No pictures or figures. Some of the tips are useful but should probably be used in conjunction with a more basic guide.