McLeod's Swimming Anatomy is getting perhaps a little bit aged, but is a really good book. Comes with the exercises on DVD if you have a player for that. (I loaned the book once and the DVD got lost.)
I did some coaching while in Grad School (exercise science) and helped with their weight lifting program too. This book made it easier for the swimmers to understand the reasons why they were doing certain exercises (which goes along way for adherence and motivation)
https://smile.amazon.com/dp/0736075712/ref=cm_sw_r_cp_apa_fabc_YYOWFbRKQ34YG
Also, I got into designing swimming apparel as a side hobby, and sorry for the shameful plug, but you may like some of these ;)