This doesn't really answer your questions, and I'm not sure what your bylaws say about resignations, but from what I remember from Robert's Rules, it is the secretary (and only the secretary) that you should send your resignation letter to. Do your bylaws state that you send it to the president?

I want to do this by the book so here is what I've done so far:

According to the bylaws a resigning officer should give notice within 10 days of resigning(this is from memory). I have notified the Pres. via email that I will be resigning but I would like to have a letter for the record. I tried to write one but it seemed very brief. Should the letter would be brief? I am afraid if I go into too much detail it will not sound right.