dear blah, this letter is to inform you i am giving two weeks notice that i am leaving my job. This will make my last working day --/--/--
Thank you
Fabemmy's husband
I think it really depends on how polite your husband wants to be when writing to his current employer. He doesn't really have to give any information other than the date he intends to leave. However, it might be politic to give a bit more information - you never know, he might want to return one day.
I'd agree with above, just a polite last day of service is required, the reason not really at that point. Many places do an 'exit interview' when staff leave and they would normally ask then if there was a specific reason.
Yes, I would add a bit about how much he has enjoyed working at Dash and Blanks and that he wishes the company well for the future. Just some polite fanny but unless you actually have a complaint or something going in with the company, its as well to leave them with a smile.