After rereading this thread I think, there are a lot of interesting suggestions in it, like categorizing more deeply this article. Maybe it would be worth to add also more tags to the books, like for beginners, good for preflop game, post flop and so on.
In my opinion it should be editable by the users somehow to make comments or tags to the books.
But there is one thing, that I pretty often read in this thread. That the people state, that they do not read books and think, that poker books have no value for them.
Honestly, I can't understand this, as I am reading pretty often books. Well, of course not only poker books. But for me books are just another mean for learning.
I love to read books before I sleep in bed. I can calm down with them and afterwards I sleep. But for me the books also have the advantage, that I do not need to rewind them somehow like a video or an audio book. I can read and learn in my own tempo. I don't want to say, that video training material is bad or audio books are bad, not at all. I use them too and it is just another way of learning in my opinion.