The diets definitely can be confusing - there are so many... GFCF, Specific Carbohydrate, Body Ecology, Feingold, etc. However, after lots of research and implementation with my own son, I do find that they carry many of the same principles and if implemented step-by-step can have profound impacts.
The best place to start if you are considering nutritional interventions is with a consult with someone who is qualified/knowledgable on the subject matter. I suggest checking out the BioBalance Program. The program will provide you with the information necessary to help you decide what/how/when to make dietary changes.
Check it out:
http://www.butterflyeffects.com/services/bio-balance-program.aspx