Never mind chosing your own books, one of the most difficult things you can do is choose books for other people (or their children).
I've been reading Four to Fourteen (Kathleen Lines) while researching another project and it's a fascinating little glimpse into post-war life. The author, an experienced librarian, covers all the books that are judged 'suitable' for a child while omitting the lighter series fiction read with such often concealed pleasure like Elinor M. Brent-Dyer or E.J. Oxenham (I can't include Enid Blyton in my list now that I've grown up). I won't say guilt - feeling guilty about reading seems to be such a waste of good reading time. Four to Fourteen is on the worthy side and is a little sniffy about school stories, pony books and the like, but does cover interesting family adventures by Arthur Ransome and Noel Streatfeild. It also includes Violet Needham (whom I can't seem to like) and Alison Uttley's A Traveller in Time which I can't reread often enough. That and The Children of Green Knowe were read to bits and now I've replaced them with even more treasured hardback reprints.
I'll continue this later as I'm now beginning to wonder, with a free hand in the bookshop, what would I buy for a child today?