I think the reason you are having trouble finding answers is because the answers to your questions are very broad. Most of the very basic care for a horse is the same across all disciplines. However, food and water intake (diet), supplements, work schedule, tack and equipment, and training methods all vary at least a little bit from person to person.
You are probably going to get different answers to each of your questions, depending on who you ask.
For example "How old should you break and start training a hunter jumper?"
This can be answered in many ways. First off, you never start specific breaking until you've got your basics down, and each horse learns at a different pace.. The horse first needs to know how to walk trot and canter. I have heard people starting to lightly break at 2 years. But then again I would personally wait until at least 3 to even consider a canter under saddle. I wouldn't jump them or work them hard til their knees closed. So it really depends.
Same with frequency of training. Some people work their horses 6 days a week, some maybe only 2 or 3.
The hardest question of yours to answer would be the basic training process. There are probably hundreds out there, and they all vary. But the general consensus is this: Groundwork, introduction to saddle work, then saddle work. How these steps are carried out, however, is highly debated and there are tons of different ways to do it.
Sorry, this may not be the answer you wanted, but there are so many variables here, and that's if something didn't go wrong in the process of breaking.