First of all, I agree with many of the people above that I commend you for seeking advice at the beginning for the road that lies ahead... I'm sure it will provide insight, and a measure of comfort hopefully.
I don't have CF myself, but I feel like I do many times because I have been with my husband for 13 years (since we met at age 15) and he was diagnosed at 3 days old so has been fighting it always! Some of the things I have witnessed as his partner, and also being very close with his parents, are:
1) although they were extremely well-meaning, they are very religious and have 'believed' for his healing from birth and often brought him to church services where they believed in faith healing and prayed for the sick.... this just led to feelings of deep guilt that something was 'wrong' with him, or God didn't love him, since he never was healed. Try to avoid that.
2) I don't know the ideal time to be honest about it, but for males, they need to be told at some point about the extremely common sterility issue for men. Despite ALL his knowledge about the disease, that fact was kept 'hidden' til he was well into his adolescence and was a devastating blow that he didn't know existed until after we had fallen in love & just led to feelings of inadequacy
3) encourage them to talk about the disease and lean on those friends that will rise to the occassion and truly be there for them in thick and thin
4) DREAM BIG... my husband was told he would never graduate high school, then of course never college, and this December he is actually finally finishing his Master's degree in Physical Therapy. It's still amazing to me.
5) On the practical side, with the ENORMOUS financial strain the disease can cause, look into "hospital indemnity insurance plans." They are policies offered by major companies that pay a daily amount directly to you for any days which you, or a specified dependent, are inpatient hospitalized. We discovered these about 5 years ago and they are truly a life-changing financial supplement. For example, inquire with AFLAC and Physician's Mutual and National Benefit Life - there are always waiting periods (usually 1 year) for pre-existing conditions (which we always disclose CF on the application), so you might be paying a couple hundred dollars in premiums for a couple of years, but after the pre-existing wait period is over, the policy pays you for example $200 per day, every admission. It really does work - you file the claim with the company after discharge from the hospital and submit the required documentation (for ex. hospital bills and doctor's note) and they really do mail you a personal check for however many days were inpatient. I know for my husband who can easily go inpatient for 10-14 days several times a year, this is WORTH every penny in the premiums. Just remember, this is to help provide the $ support for medications, vests, parking at the hospital, prescriptions, etc... not to buy the family a cool new car. Unfortunately, some people we have known use that income, in my opinion, in an extremely poor way.
6) LOVE him without restraint, and laugh til it hurts.
My prayers & hope are with you,
Elizabeth - Houston, TX
28 year old wife of 29 year old CF