Sometimes too much info confuses the matter.
This.
I completely wore one out after years of it living in a tackroom, it disintegrated. The new one lives in the house now and is liberally decorated with scraps of paper marking relevant ailments. It may not be right up to date but I get the gist of it, and as it, and my Vet are of the same generation it works for us.
The internet is great, but often a huge source of conflicting advice and opinions - take simple rain scald/rot for one. One article states it is is contagious and everything should be isolated, another gave more useful advice on symptoms, cause and treatment, and a half dozen others said other things.
Although i look on the internet as well i know that i can trust this book, there's a lot of false information on the net
Another vote for this, it's my bible and lives in the car!
^^^this
^^^this, just because it is not up to the minute, it gives you a broader perspective.
LOL I binned mine, cos it was so out of date, but it had handwritten notes of my early ailments, when I was a newby owner , sighI quite like my TV vet book - its from 1974, so for most things it recommends euthanasia, but has good pictures !!