To organize our music reading studies, we use 3 fretboard zones.
First we learn the naturals in zone 1. In this first map, we have the naturals grouped by string, in notation, with spelled out tab below [number in a circle is a string, number above is fret]. Above that we have the note-tone name, then note-head location. The minus signs are 'this many' below line 1 of the staff. We can see that -4 is the only 'space-only' note. All of the others go Line-Space. For 5S, we could go with +1S. And other notes can be described in different language.
For the notation, the 'whole note' is the lowest note on each string [which are the open strings], the quarter note heads with no stems are the fretted note-tones on each string.
These notes in first position are the C Major scale. The key/scale of C Major contains only the naturals [no sharps or flats].
And here is a fretboard map of the naturals in zone one.
Fret numbers are indicated along the top. Each fret space has its corresponding note head location on the staff. The note heads are written as whole notes, yet, you will see these notes written as many different types of durations.
We can call notes not only by their letter name, but also as low, middle, or high.
The line between low and middle is between the B and the C. By calling the B, Low B, we can then call the the next octave up, Middle B, and the next, High B [not shown in these maps], and the next and last one on the board Highest B [also not shown]. Therefore, the line between the middle and high registers is again found between B and C. There is a Higher and Highest register.
Middle C is normal nomenclature; as well as others such as High E.
In most learning systems, all of the tones aren't labeled the way that I have chosen, so you may see different naming from other sources. By naming the notes, we know we are talking about a specific note, which translates to particular string & fret locations.
Once we know the naturals, the sharps [#] and flats [♭] are modifications of the naturals.
Fret numbers are indicated along the top. Each fret space has its corresponding note head location on the staff. The note heads are written as whole notes, yet you will see these notes written as many different types of durations.
And, double sharps and flats do exist. F# is E𝄪 [𝄪 = double sharp, sometimes we will see an x]. F is G𝄫 [we write 2 flats for a double flat].