jackrose, the failsafe website is a great place to start, lots of info on there, just google failsafe and it should come up I am not sure if I can post a link to it so I had better not.
There is so much to learn about the things to avoid and it can seem restrictive but I think at the end of the day you read all the info and make a decision on how you would like to approach it.
I have avoided doing an elimination diet with DD but so far just reducing or eliminating the ones I know affect her we have had a huge chancg in her behaviour, some people see no real results unless they do the elimination diet.