Most of us have seen at one time or other, that one way to initially learn how to identify the notes on a staff are to separate the notes located in the spaces between the lines and then the notes located on the lines. The notes in order on the lines are the initial letters of the phrase:
Every Good Boy Does Fine
Because the 12 hole chromatic has a range slightly higher than that, I would suggest memorizing
EGBDFAC I'll let you make up your own phrase. Mine is:
Certainly, Every Good Boy Does Fine At Cars.
And for the spaces most people say memorize
FACE, but again the range of our instrument reach a bit lower than that and a bit higher so learn DFACEGB
These are of course just crutches to get you to the point that you can simply look at a note position on the staff and know its pitch value. I found separating the "space notes" and the "line" notes was slowing me down, so I have begin thinking of ways that combine them. So memorizing the "word" CDEF and GABC helps. Learn to know the note on the first "dropped" line is a C and the first note above the staff on a Line is an A. It is easy enough to memorize that B is on the center line and therefor the notes AB and C are obvious. These are all just initial crutches until your brain simply looks at any of the notes and knows the pitch name without using any of the hints. I am not there yet, but almost. I can certainly already name any note with a brief thought.
The above image shows just 2 octaves, you display all 3 octaves of the Chromatic 12 hole harp, you need the following:
D is the note below FACE... :)