My only add is to the editing - Whether you self edit or use an editing service, listen to your book....several times. If using Word, use the Read Aloud command. If not, there are numerous free programs to listen to your manuscript. Very important.
I learned this after I started doing my own narration for audiobooks - I not only caught typos that the editor did not catch but also lines or words that might create a stumbling block for readers (if they have to read a sentence twice to understand it, it stinks).
Have fun!
Outstanding suggestion! Thanks!!!