Academics will usually give you a long list of books and articles as prerequisites to reading anything, but I don’t want to do that. I would just advice the interested readers to not trust too much in the latest update of this or that textbook. I recommend reading originals, especially as many of these are available online and, therefore, are widely referenced in various discussion fora. Also, when you would have an issue with this or that interpretation, you will find you will be able to google for help very easily.
Feynman’s Lectures is and remains a classic for me, especially because it’s available online. Some of his Lectures on quantum mechanics – such as chapter 4, on identical particles – suffer from excessive and speculative generalization, but even this chapter makes you think for yourself. That is very valuable, in my humble view, because I find more modern textbooks often too confident in their approach: they emphasize what we know, as opposed to what we don’t know.
Feynman’s Lectures also have the advantage that you get the math you need with the physics you study. However, in case you’d want a good mathematical introduction, Mathews and Walker’s Mathematical Methods of Physics, is a reference that stands out.
As mentioned in the introduction, Dirac’s 1930 Principles of Quantum Mechanics is still worth reading, as the basics haven’t changed. Of course, it covers the QED sector mainly, and there is not a single illustration or diagram in it. QED as a procedure, in other words. But that’s what’s standard quantum mechanics is, unfortunately.
For QCD, and the other sectors of the Standard Model, you will probably want to consult the reference in the field, which is Aitchison and Hey’s Gauge Theories in Particle Physics. Its 4th edition includes all latest developments and discoveries, including the theory of the Higgs field. In fact, the latter is what I am going to explore and blog about. 🙂