Looks at the FB sourdough group I'm on and sees Artisan Sourdough Made Simple (Raffa) being recommended - I went on a course and have the handouts so don't (yet!!) have a book
Coincidentally, I've started a starter today. Not really done much with sourdough but I'm lusting after rye bread which needs sourdough if itsa lot of rye. Friend lent me a sourdough book, I've only looked at the starter bit yet!