What I found as a newbie writer (in 2011, when I joined) was that after a while any book I read was just largely repeating what I'd read in other books.
On Writing helped because it shows clearly that no matter how much technique you learn, you have to write about yourself, what you know. That could be space opera to horror, poetry to lit fic. Your creed, ethics, experiences and values are what you're really writing about, dressed up in your genre.
My wip isn't really about a haunted house but my values and opinions on racism, appropriation and organised religion, which come from my experiences as a specialist teacher working with challenging behaviour in inner city London schools!!! But I love supernatural horror so that's how it's expressed. Furthermore as a depressive, my outlook can often be very dark but it has given me (I believe) a sensitivity to the bitternesses and sweetnesses of life.
Anxiety, depression and PTSD have made me the creator that I am.
Chrons has made me the technician I am (strive for).
So, I'd personally read a how-to book, maybe two, but moreover participate in our monthly writing challenges, and frequent the crits forum.
pH