The professional way to tell your employer you are leaving is in writing.
Simply say, "I am submitting my resignation today. Thank you for the opportunity to work here," and hand them a short note that reads:
Your Name
Your address
Your city, state and zip code
Date
Recipient
Title
Company
Address
Dear Owner or Supervisor's Name:
I want to thank you for giving me the opportunity to serve as JOB TITLE at NAME OF COMPANY. I have learned a great deal about NATURE OF THE COMPANY'S BUSINESS during my time here and will always value this experience.
However, the time has come for me to move on. This letter serves as my formal resignation as JOB TITLE My last day will be TWO WEEKS FROM THE DAY YOU RESIGN
I truly appreciate your guidance during my time employed. I will do my best to ensure a smooth transition and look forward to your direction to make that happen.
Sincerely,
YOUR NAME
Keep in mind that your employer may decide to let you go immediately. But the professional thing to do is give two week's notice.
Good luck to you