Best Rest Products in the USA have a free e-book download available titled ‘How To Ride A Motorcycle Off Road, Riding Techniques for Large Dual-Purpose Bikes’
To quote from the Best Rest site:
We wrote an Off Road Riding “primer” that gives you the basics. Reading this book won’t make you an expert Off Road Rider, but it might teach you a few things. No matter your skill level, you’ll find something useful on these pages.