I have proof read a number of Camino manuscripts over the past 20 years (not any more though).
Join the Camino Athors group on Facebook where you can ask for help or join podcasts on self-publishing, editors and other useful subjects. Some useful tips:
Before you start writing, try to avoid a few pitfalls.
Which is the most common Camino route written about?
Camino Frances
What is the most most common title of a Camino pilgrimage book?
Buen Camino and Way of the Stars
What is the most common photograph or artwork for the cover?
The Alto del Perdon metal sculptures
What are the most common mistakes made in Camino pilgrimage books?
Spelling errors. Misspelt town and city names, incorrect Spanish names, Saint's names etc.
What is the most common adjective used?
Very. Find at least 24 adjectives to use instead of 'very'
What is the big NO-NO when writing a Camino pilgrimage book?
Plagiarism. Copying text from websites, books, academic papers etc without giving credit to the original authors.
BE CONSISTENT
Create a style sheet so that you are consistent with how you write numerals, times, dates, distances, decades, centuries and Spanish names etc. There is an example in the FILES.
EDITING
Find a good copy editor who know the Camino you are writing about and will ensure that the facts, spelling (especially Spanish gender specific words), punctuation and grammar are correct.
Find a good proofreader. This is the final edit of the copy and the proof reader will check all of the above as well as ensure that you have used the same font style and size, text spacing, ., before you publish.
I have read books where the author meets up with a pilgrim (say at Astorga) who she first met at the Cruz de Ferro. (muddled geography!) The volunteer in an albergue is a 'hospitalero'. In one book the author used 5 different words - 'hospitaler' 'hostelero' 'hostelleria' etc.
TIP: It would be helpful to ask a friend or colleague who has a good knowledge of the Camino you are writing about to check your facts, the geography, mileages, spelling etc.