One of my early Orchid books was and still is Home Growing Orchids by Rebecca Tyson Northen.
I had in my hand the other day, thinking of the way she lists the different types of Dendrobiums so Icould perhaps add that to the Names Game thread. It was too complex to add just like that, but I really wished one could just make a quick copy of those pages and post them. I guess, one has to read it it.
Amazon sells some very cheap used copies of the book. It doesn't have the glossy picture look of more modern books, but it still contains a lot of useful information.