Mrs Victor Hurst's wonderful book is written for children, but will be enjoyed (and found to be of practical use!) by anyone - it is well written and from the author's extensive personal experience.
I can't think of a better way to recommend it than by including a chapter, so you can appreciate the quality of the information it contains. So here is the author's advice on "Choosing a Pony" (chapter III).
In addition to practical chapters like the above, there is interesting background about the origin of the horse, breeding and different breeds of pony (all written in the same friendly and easy-to-read manner).
This being an English book of a certain age, there are some wonderful sections of interesting rides around the country and lots of practical and historical information about hunting.
And some wonderful inspiration for showing types...
The alternatives to hunting are considered very much secondary, but they are covered. There is some superb advice on preparations for a pony camp, still relevant and very helpful for anyone involved in something similar today.
This sort of book is exactly my cup of tea - heaps of vintage charm, beautiful illustrations and the sort of information that was relatively commonplace in good yards back then but has been mostly forgotten today.
Brilliant.