Prepare for It. In this case, all you can do is politely deliver your resignation, then strive to make the transition as easy as possible for your team. Your manager may not have the ideal reaction to your news__and your workplace may not be the most pleasant environment for the next two weeks__but to avoid burning bridges, it's best to work through it with a positive attitude.
However, at most companies, there's no formal requirement that you do so. Most employment in the United States is called "at will", which means that your current employer can fire you at any time and for any reason (except those that are prohibited under law).