Need help finding articles

My BO/Trainer wanted me to make a binder of horse information on stuff like how to tell if a saddle does NOT fit, and so on, but I can't seem to find any articles on it.

If anyone knows any articles for the following:
1) how to tell if a saddle does NOT fit
A) too big
B) too small <---most important one I need
2) Importance of warming up a horse (this is for some of the girls riding at the stables)
3) What causes the white marks on the withers (yes I know this, but my BO wanted to know about this)
4) Proper collection (yes I could find articals on this...but I need something a 13 year old can understand lol)

Any anything else that is important about riding or the care of horses...or anyhting just plain interesting. Thanks a ton

http://www.equisearch.com/horses_rid.../eq9points447/

http://www.mastersaddlers.com/

List telling what to look for if your saddle doesnt fit:
http://saddlesthatfit.com/BadFitSymptoms.htm

thanks Vida!!!!! Those helped!

I tried to find some links but the ones I found, are the same as Vida. Why not also look at links that show proper fitting? by doing so you essentially get bad fitting as well.