In terms of 504/IEP and ADHD, this is a good article.
10 Common Myths That Some Schools Purvey
ADDitude Magazine fall 2011
Matthew Cohen, JD

I don't know how to link it here but if you google it will come up. Even to get an IEP, kids with ADHD just have to have their educational performance adversely affected compared to their peers (this generally means they are slow to get work done, or are not getting the work done). The school district is arguing with us about that as well, but all they need to do (according to the State) is to document how slow DD is and how that impacts her. Grades/achievement scores are a factor, but not the only thing. Right now she has a 504, which is generally for kids who have a documented disabililty requiring accommodations which could be anything (like a kid who is in a wheelchair and needs help with doors). Generally IEPs are for "more" impaired kids who need more in terms of actual specialized services/instruction.