1. Confirm That You Actually Have a New Job.
Any job offer can be rescinded unless you have it in writing. Sometimes employers place holds on hiring at unexpected times or employees the organization was going to replace end up staying. At any rate, life happens, and an employer doesn't owe you anything until you have the offer in writing. So if you're worried that you might be walking into something insecure, get an agreement in writing if the employer doesn't offer it. If you don't, you could end up making a very regretful mistake.
2. Keep Your New Job to Yourself Until You Pack.
The truth of the matter is you need to be ready to hit the road when you submit your two-week notice. This means that it's probably not wise to inform your boss that you're going to leave as soon as you hang up the phone after speaking with your new employer. Many employers can become, dare I say, paranoid when you tell them that you're leaving their ships. The second you inform them, you become a member of the "other" team in their eyes; you're no longer one of them. They may feel somewhat betrayed and want to protect themselves from any harm—"harm" meaning the possibility that you might steal sensitive information and files, etc. So understand that and act accordingly.
Before you deliver the news to your boss, look around your office and sift out the items and supplies that belong to you (meaning things you purchased with your own money). For the next day or two, slyly pack and transport your possessions—because when you give your notice, you may only have a couple of hours to get out.
3. Save it.
Go through your computer and/or cell phone and save any important industry-contact emails or phone numbers now. Of course, keep your integrity about you, and do not overstep the boundaries of intellectual property and confidentiality, but don't sacrifice your valuable contacts. Also, make sure you extract any personal documents and/or photos from your computer. Your employer could disable your email and company cell phone immediately after you submit your notice.
4. Submit a Written Two-Week Notice.
When you submit your resignation, make sure to bring a formally written letter of resignation rather than simply saying, "I'm leaving." It's just professional. Plus, it protects the company from having to pay you unemployment if you want to be a jerk later and claim you were fired, so many employers require resignations in writing.
The letter should be short, sweet, and to the point. Make sure to state what your final day will be (two weeks' notice is standard), and thank your employer for the opportunity. You can quickly mention your positive experience with the company, but don't ramble on. This sort of letter is only meant to be a few sentences long.
5. Leave on a Positive Note.
Like I said, people's true colors always show when they quit jobs. Many people simply put in their two weeks' notice and don't even say goodbye to anyone. That's just shady, and if you do that, you may as well flush your business relationships with the coworkers you're leaving down the toilet. Don't be one of those people.
Before you leave, make sure to thank your colleagues and employer for the opportunity to work with them. It's always better not to burn bridges, no matter what. The world is just too small, and it can prove to help you tremendously later in your professional career.
