I did a google search and found this "training tips" from someone at the University of Washington that's still active:
As a Harris’s hawk breeder, I get a lot of calls and emails regarding the training of captive-bred Harris’s hawks. Many of these inquiries come from falconers obtaining their first Harris’s hawk. It is primarily for these falconers that this article is written, although I do hope that even experienced Harris’s hawkers will find some valuable tidbits of information or alternative points of view to stimulate them.
I am a scientist by profession, so naturally I try to draw my conclusions on Harris’s hawk training using the scientific method whenever that is possible. Inevitably, because of the modest number of Harris’s hawks I have flown, a good deal of intuition creeps into the equation, too. Consider what is written below to be one person’s (informed) opinion.
Let me say from the outset that there is more than one "right" way to train a Harris’s hawk and end up with a highly desirable finished product. I am still learning new tricks every year and incorporating them into my "standard" training routine. I have seen exceptions to nearly every "rule," including my own training rules. I’d love to hear from you about your own views and experiences training Harris’s hawks.
The methods described in this article have worked well for me and many of my hawking buddies around the world, hunting in a wide variety of terrain for many different quarries. My comments are based on my 28 years of hawking with 31 captive-bred Harris’s hawks (with more than 3500 head of quarry taken), plus careful observation of dozens of other falconers and hundreds of Harris’s hawks. I have made more than my share of mistakes along the way, and been witness to the mistakes of many other falconers, but hopefully I can help you avoid learning everything the hard way.
The author is Toby Bradshaw and has his e-mail on the link above.