You can find some great books on braiding and knot work at hought.comI would recommend “The Art of Braiding, the Basics Revised Addition” for the beginner.The books consist of detailed photographs, directions and make for a great reference.At y-knotlace.com you will find the Marlinspike videos by Robert Black.A good video to start with is Decorative Knotting & Braiding in Leather. You will get step-by-stepdirections that are easy to follow. He will also teach some basic knot tying skills. These skillswill be useful for dog leads and a variety of other projects.Knottactical has some fantastic youtube videos to help you learn knot tying.
Leads N Leather also has a Youtube channel with helpful videos https://www.youtube.com/@leadsnleather
If you already know how to braid in the round this is a very helpful group. Facebook Group Kangaroo Lead Making Mentorships and Supplies https://www.facebook.com/groups/4098773016841375
Facebook page www.facebook.com/leadsnleather
Instagram page www.instagram.com/leadsnleather