Here are some randomly selected joke topics beginning with the letter 'N'
Nothing
Knock knock
Who's there?
Scott
Scott who?
Scott nothing to do with you.
Numbered
Why was the calendar sad?
Because its days were numbered.
Nothing
If you have nothing to do, please don't do it here.
Nuisance
My dog is a nuisance. He chases everyone on a bicycle. What can I do?
Take his bike away.
Notice
I've got a bad stomach.
Well just keep your coat on and on one will notice.
Notice
Notice - If you notice this notice you will notice its not worth noticing
Nothing
I started out with nothing...and I still have most of it left.
Nurse
Doctor: Nurse, I'm ready to see the next patient now, can you send her in?
Nurse: Sorry, she didn't look very well, so I sent her home.