The Australian Professional Association of Climbing Instructors, (PACI) has a deep collection of technical articles on knot tying. (Would you believe a 76 page article on just the bowline?!) If you’re a rigger, rescue professional, or a citizen climber with a curiosity about rigging methods, this website is a great place to start.
Many of the articles / papers are written by Mark Gommers, a man who clearly takes his work very seriously and a guy I would love to meet someday.
Climbers should probably start with article number one at the top, simply called “Knots”. It's described as a: “Comprehensive compilation of life support knots - includes test data and tying methods”.
(Note: some of the PDF files are password-protected, but if you use the link below, they tell you the password most of the time, so access is easy.)
A rainy afternoon, a length of rope to practice with, and a big pot of tea are recommended accessories.
Here’s one page from the “Knots” article as an example. The below image is copyright PACI.com