I am not exactly sure, if this should be really done by going meta but I want to attract your attention to a question that has been asked many times in pretty much all possible way : Should I wait to leave my company after I finish a big project? What's the best way to do this?
The answer provided is the most excellent and complete answer on the matter I have seen as it emcompass the process to follow and also how you should behave professionally and also on your own interest (like not burning bridges). I think we should make it a canonical answer and add it to the relevant tag (job-change, resignation ?).
And for those that say "what is the best way to do this" is attracting opinions. Just read as "what is the professional way to do this".