Here you will find plenty of places where you can get support, information, and strategies for success. You may find that you will benefit from these resources most in terms of what they can offer you as to what on earth you can actually eat on the diet.
A qualified dietary professional could be a dietitian, a health coach, or nutritionist. You would just want to make sure that they have received training as to how the diet works.
This book not only provides you with well-researched information as to how to follow the diet but also provide you with a wide variety of recipes:
The Everything® Guide to the Low-FODMAP Diet
Modify Health offers Monash certified foods that you can order online, and they ship for free anywhere in the U.S. Another company that prepares and ships low-FODMAP convenience food items in the U.S. is FODY Foods.