Chris,
Although quite a bit of money can spent on building up a library of books, it will be money well spent.
None of us know everything, so we need books as a source of information to which we can refer.
Some books will be opened more often than others. That will depend on:
the state of your knowledge
what you want to do
how often you wish or need to perform that task.
As an instance, if you bash on regardless, you could spend more on replacing broken Taps, and spoiled workpieces, than if you had bought a book on Taps and Dies, and how to use them. Which just happens to be No 12 in the Workshop Practice series of books.
Other than for interest, there is not much point in buying books on the vertical milling machine, if you don't have one. Some of the info MAY be useful if you use a vertical slide to do a little milling in the lathe.
L H Sparey's "The Amateur's Lathe" is often cited as a good starting point, (Although this heavily features the 7 Series Myford, because this was almost the standard machine, when the book was written ) just as is Ian Bradley's "The Amateur's Workshop" and Tubal Cain's "Model Engineer's Handbook". This latter sees a lot use by me, and I've been in Engineering since 1958!
When you find a need for a book, buy it. You will refer to it more than once, although some less than others, but it will be there when you need info on that subject.
Find your local Model Engineering Society, and join it. There will be folk there prepared to guide you on your machine, or show you how on theirs.
You ask questions, in the hope of gaining knowledge, not to be laughed at. If I need information about my eyes, I ask an Opthalmist. I am an Engineer, not a medic. Should I wreck the control board on the mini lathe, I shall consult someone with good knowledge of electronics.
Keep climbing the learning curve.
Howard