Food preferences are often mentioned in books, but it just ain't that simple. Certain things grow in certain areas, and are only available at certain times and may (or may not) be preferred by the local herd. 2 examples are brassica and pokeweed. Some herds love brassica and others won't touch it. My deer hammer pokeweed. It's naturally occurs and I promote it's growth when I see it. There are dozens of examples of different herds preferring different foods.Any book recommendations?
Learning observation skills are better than just reading in a book that deer like to eat "X". Learn to recognize what deer browsing looks like as opposed to some other critters. Deer have no upper front teeth, therefore when they bite off a bud, the end of the twig will have a rough, ragged end. Rabbits, groundhogs, etc leave a clean bite on the twig almost like it was cut with pruners.
Also learn to see browse lines. A browse line is a visible change in growth that starts at around 5 to 6 feet off the ground. Everything below that line gets eaten and everything above it is out of the deer's reach and so the vegetation remains. BTW, a well defined browse line is often a sign of too many deer for the available food supply.
Examine deer poop. Poop from deer that are eating woody browse tends to be loose pellets and poop from deer eating more palatable vegetation tends to be softer and stickier.
These are some very basic things to look for, there is no secret to that stuff. But for a novice, these things may not be so obvious.
My point...Books are great, read, absorb and apply everything you read. But if you don't learn observation which can take years to learn, all the books in the world aren't gonna help you roll with the things you encounter.