8 yr old with ADHD

my 8 yr old was Diagnosed with ADHD in 1st grade. i did not know very much about it so i started by typing in ADHD in to google OMG i was like where do i even begin to start.... but i just went full steam ahead and started reading and i still to this day learn more and more everyday. My son is now in 3rd grade he has a great teacher but my son has had the hardest time this year ... He is not an angry ADHD kid but he id a normal one :) he just has the hardest time paying attition to really anything he is smart and right were he is suppose to be for 3rd grade level but the not paying attition and not completing his lessons is really starting to take a toll on his progress... he is falling behind in studies and having to be removed from class groups cause he is bothering the others ... Yesterday i went into his Classroom after school cause he forgotten to get one of his notes off his desk and when i walked in i was like why is you rdesk moved away from the rest off the class again and he said i was bothering the other kids, and then i also asked why there was a divider around his desk too...  he said cause i was not working and i needed to have no distractions .... i was like ok understand where the teacher is going with all this BUT there has to be another way than just Alienating him from the rest of the class, i am so scared for his we live in Kansas and their is the no child left behind act here so they can't hold kids back a grade ... so he is going to go on to 4th grade and struggle even harder there so what i am asking for is some help, opinions, anything anyone can give for me to help my son so he can Succeed to his fullest, and still enjoy life and his friends. i want a way to help him understand what he has and how to handle it!

thanks
Angie