I am still starting out, myself, so I'll tell you what I did. A few years ago, I ordered a beginners kit from ubraidit.com, including the book "How to braid Quality Custom Tack". I made many projects using paracord. Than last winter, I ordered a "Complete Beginner's Braiding Kit" from Gail Hought, which included many practice roohide strings, a fid, bone folder and book "The Art of braiding: the Basics." It was expensive, like $350 or something. Not much learning transfered from the paracord to roohide braiding, becuase I never did any buttons in paracord - only flat and round braids (of which the 8 plait transfered) - the terminal knot also was common to both. I have since ordered two more of Houghts books (also expensive - $50 each) and the complete Key fob kit - which included materials for over 20 buttons placed on leather key fobs. The books can make you mad if you only have one - they keep refering to others in the series. The illustrations and directions worked great for me - I would have never started if I had only Grant's "Encylopedia of Rawhide Braiding". I have also started cutting my own strings of rawhide using a Hanson string cutter ($450) and rawhide from Tejas Industries ( $90, including shipping for a "side"). So, all-in-all, I have spent over $1000 so far trying to get to my ultimate goal of braiding rawhide bosals. I'm getting damn close, too!
You can do this much more cheaply by finding online tutorials and perhaps buying something like the "Aussie Strander" to cut strings. You can learn all of the buttons by simply using paracord and taking the core out to flatten it. Best of luck!