The Quick ID notes look good. You could mention the spiney shells on the nuts and the fact the nuts are edible. Empty shells can be found around the trees in the winter. When doing the quick ID notes, I would recommend including just those specific charactersitics that make the species distinctive from other similar species. Too many books keep every description structured the same way in the same order. You can't tell what features make them distinctive and what ones are mundane and non-diagnostic. Ask yourself what single feature makes this species distinctive from all thesimilar species - that should be the first tip in your Qucik ID. For beech - the smooth bark pretty much nails it. How many species are you going to inclde in your completed book? Do you know which ones yet? Are you including both exotics and natives found in the NYC Parks?
"I love science and it pains me to think that so many are terrified of the subject or feel that choosing science means you cannot also choose compassion, or the arts, or be awe by nature. Science is not meant to cure us of mystery, but to reinvent and revigorate it." by Robert M. Sapolsky