I found this website with short video clips of different breeds of chickens (and ducks, guineas, etc...). The videos I was looking at appeared to have been taken at a poultry show in Europe so the animals are very nice representatives of the breed. It was helpful for me because I could see how the animal actually moves - much different than looking at a two-dimensional representation. Enjoy!
http://www.mypets.egzoticpheasant.com/browse-chickens-videos-1-date.html