As Seana and CFHockeyMom said, go print the Guide off of CFF.org and talk to your CF Center (doctors and socal workers) about any information they can give you. Get it for each teacher. Once you know who his teachers are, it might be easier to make an appointment with them, that way if they have any questions they can ask you and you know they got the information and looked at it and not just took it and tossed it on their desk. Ask your son if he wants to go or not, it might be easier with just you and the teacher but nice to ask so he feels included or doesnt want to be in that situation. It can be his choice. Also talk with the principal. Its always good for them to know, specially if he has more sick days than he should, the principal see that he gets his work (hopefully he will stay well and that wont come into play). Something else to think about some schools dont like kids to take medicine on school grounds. I had a doctors note (saying what I had, I knew alot about it, had medicine and could administer it myself) that I carried around with me at all times (wallet/purse) and was also on my school file. So if a Substitue came in and wouldnt let me take what I needed, I would go to the principal and they would fix it due to my note (this came in handy because I was written up once due to walking out and taking medicine after the Substitute said not to even though I explained the note, due to this note being on file I got out of it and nothing was on my record.) Do all of these appointments/meetings as soon as the school year starts so there will be (hopefully) less problems as the year goes on. I also recommend doing this every school year with the teachers or if a teacher is replaced mid-year. That way they cant say they didn't know.
I even continued to give teachers information through college.
Hope this helps!