Resignation letter: general tips and what to do if boss is not on site?

Question

Somewhat related: How to Deliver Resignation Letter To My Boss Who is Not Located on Site.

At the company I work for, I have a boss (the president of the company) and a supervisor. Unlike the related question above, I do not have the option of contacting my boss other than via e-mail. The boss will not be back in the country for another week.

On Monday, I will be accepting an offer for a new position, and I intend on putting in my two weeks immediately after to my supervisor. My questions are:

1) Should I e-mail my boss to let him know of my departure, or would letting my supervisor know suffice?

2) Should I include anything in a resignation letter other than a more formal version of "Dear X and Y, I will be leaving at date Z to work at [some type of company]. Regards, Me"? [I apologize if this question is too broad, but I have no experience in this whatsoever, and I have had inconsistent advice.]

Answer 1

Ordinarily it's fine to give notice to your direct supervisor. There's no need to copy the company owner unless you have some particularly close relationship with him.

If it were me, I would write this:

Dear (Supervisor):

My last day with (company x) will be (whatever). I am grateful for the opportunity to work with you over the past (y) years.

Sincerely,

(your name)

It is a good idea to say "thanks" for the time you spent with these folks.

It's best to avoid explaining in writing where or why you're going. That's because it may give the impression that you're interested in some sort of counter-offer negotiation. Maybe you are interested in a counter-offer. But, if you're not, it's best for everyone's dignity just to say "I'm going" and leave it at that.