You mean recommended reading for learning more about the notation? I don't really have any such recommendations, no. My opinions on notation definitely don't represent the rest of the music community, but for what it's worth, I think it's a mess. :P
There are two arrangements of pitches that are important to think about, and you kind of have to go back and forth between the two. The first and most obvious arrangement is monotonically increasing pitch, and this is the direction that the pitches are labelled in. (C, D, E, F, G... and for chords, I, II, III, IV, V...) However, these labels skip over the black keys on the keyboard, giving the impression that the black keys are kind of a separate spectrum, when in fact the black keys and the white keys together form a consistent spectrum, and the only thing that distinguishes the black from the white is that somebody decided to give them a different color. The coloring does have significance, but not in this arrangement.
If you rearrange the keys into the "circle of fifths", you'll see that all of the white keys are adjacent on one side of the circle, and the black keys are adjacent on the other side of the circle. The most harmonious ("consonant") music uses notes that tend to cluster together on the circle of fifths.
By far, the two most consonant pitch relationships are when one pitch is exactly twice frequency of the other, and when one pitch is 3/2 of the other. The circle of fifths is the simplest way to visualize these pitch relationships. (Although I'm also partial to the Wicki/Hayden layout and, similarly, isomorphic keyboards.)
It doesn't matter much which part of the circle of fifths you use, but whoever designed keyboards picked out a region of pitches on the circle that are now the white keys to serve as a guide. Unfortunately, before they labelled the white keys, they resorted them in terms of monotonically increasing pitch, leaving uneven gaps between the labels where the black keys are. The terms "sharp", "flat", "half-step", and "whole-step" basically serve to provide linguistic access to the rest of the spectrum that we failed to properly label.
Anyway, aside from my notation rant, it's also important to understand that fully harmonious/consonant music is... kinda boring. It's like a movie with no conflict. Part of the artistry of composing music is deciding which parts to make consonant and which parts to make dissonant. Often the overall structure of a song resembles a diagram of the rising and falling tension in a story, ending with a consonant climax, and with sort of a fractal hierarchy of short, intermediate peaks along the way.