They will ask for an email address and then ask you to confirm the address. If you don't like getting junk mail, you can always unsubscribe at a later date.
a quote from their website:
LInk: Click here to download the bookThis is the most complete book available on the 1911 Style Combat Auto, whether for competition or self-defense. It features chapters on accessories, custom modifications, basic combat pistols, full house compensated guns, ammo and handloading, the proper maintenance of the combat auto, and much more. Including information and loads for the .38 Super, today’s most popular competition gun, this book is the complete guide to purchasing, modifying, and customizing the 1911 style Auto for competition or carry. Edited by Cameron Hopkins with foreword by USPSA National Champion Jerry Barnhart.