There are so many ways to do it, the only answer is to find what works for you. Every ex-smoker out there knows how easy it is to ignore every single tactic friends and families might try to make you quit unless you actually want to.
www.givingupsmoking.co.uk is a good site to look at, especially when a craving strikes
The answer to the Zyban and flying question is straightforward - it's the same with ANY form of medication, always get advice from your GP and if they don't know enough about altitude physiology to give suitable advice, then go to your AME. And do all this before taking anything that might affect your performance - 30,000 ft is NOT a good place to start finding out about side effects.