We thought our son had adhd too, he displayed every sign. We read the Kazdin Method for Positive Parenting (I'm pretty sure that's what is was called;) ) and it helped a lot. I mean it saved me from certain insanity.
They really focus on the positives that kids do, the idea is that you are rewarding the good and not the negative with attention. Obviously there are certain lines that cannot be crossed, but those are boundaries they have to learn in time.
One really big thing that has helped so much all in itself, I don't give tomeouts, I tell them they need to go to their rooms until they are ready to act responsibly. The majority of the time they go for a while and come out better adjusted, on occassion I can tell by the demeanor they need more time and have never gotten an arguement back. I think they learn to self adjust to their problems.
at 3:50 PM on Mar. 31, 2009