Well, the goal is to keep it brief. Let them assume everything else that's not required in the letter. What's required for HR is two important things. The latest you can stay before moving on (2 weeks) and why you are leaving.
Technically you can leave out the why you are leaving if you like. If you state you are leaving to do competing work, they may let you go with 2 weeks pay. That's how most firms do it. You quit giving your two weeks, instead of them keeping you around, they let you go on the spot with 2 weeks pay instead because you are too much of a risk to keep around.
Now this way is great for you because you get paid 2 weeks for not even being there but it hurts you if you ever intend to come back. It's kind of abrupt, grab all your stuff as you are escorted out right away type of stuff. You will have essentially have burned that bridge of going back. This can be critical in smaller towns where there aren't as many financial firms to work at or where there are only a few good companies worth working at or that will hire you.
Another way is to say you are working on something unrelated. Some say they are going back to school, studying for a major exam, or whatever and just need some time off for maybe a year. At which point you get to stay on for the two weeks because that's all they know and you get a friendly walk out. It's like you didn't betray anyone or the company. They even tell you to apply back later or come back anytime.
As you can see, I've seen both done. However you do it, be sure you take all your stuff home the day prior. Do it gradually if at all possible. Tell all your closest friends in the company prior as well so you can exchange contact info. After you give your notice, you could be walked out on the spot and won't have a chance to do all of this.
Good luck.
Edited 1 time(s). Last edit at Tuesday, July 4, 2006 at 10:19AM by Fx.