Donovan Waite has released some instructional videotapes about ukemi, which I found interesting. I can't remember the exact name now, though. I think the one I saw was the second one.
I started to get comfortable with high breakfalls, being thrown by the more advanced members of the group. They were able to help guide me into the proper position and offer me the strong support I needed to take a proper fall comfortably. Long ago, when I was doing Judo, for purposes of learning ukemi, it was policy that beginners did not throw beginners, as that was where there was a risk of injury. Beginners threw advanced students and advanced students threw beginners. Later, studying Judo techniques in an eclectic style, where even the more advanced students were beginners in Judo, ukemi became very hard to learn, as bad throws and bad falls hurt, causing fear, which caused worse falls, which caused more pain, which caused more fear...