Parting is such sweet distress.  You want to resign and you have to do it right.    Whatever your reason is, it is imperative to depart the job with pride.  No matter how greatly you wish to leave it is always best to bid farewell in good terms.  There is actually no set-up to follow when it comes to composing your resignation letter.  Its contents depend on your individual state of affairs.

Your resignation letter will be kept on file in the human resources office.  This would be the only record of your resignation:  make it brief, constructive, and straight to the dot.     

Begin the letter by getting candid.  Give your reason for writing and inform them what you have settled on.   Be as modest as you can be.  Individual conditions influence your reasons for leaving.   It is best not to give specific rationales for leaving, you may just state you have decided to go because of better job opportunities, you may also say you need the time for own development.  

For reference, you may have to include the terms and conditions of your contract.  You have to include the date you are intending to leave. If you need to go prior to the end of your contract period, then this is where you should inquire if it is probable.   

At the end of the letter, consider mentioning how grateful and pleased you are to have served with the institution and that it was a period well spent with them.  Be sure to assert that your time with the company has been rewarding and fulfilling. Hinging on the magnitude of the institution, you may have to put your name, department and rank. You can briefly state highlights of your work and principal achievements during your stay with them.  

To make it properly, you should draft a resignation letter to your immediate boss, and request for a meeting to tender the letter.  This discussion and the number of days that go after it will create the main impression that your direct boss or supervisor will get about your time and value with the office. Tell your superior that you will complete and handle the transition of any assignments that you are presently handling.    

Keepn in mind, it is forever appropriate to remain positive.   Your company, employer, and colleagues play a primary function with your future career.   Never cut ties nor burn bridges.