I am resigning from my current position tomorrow. How do I compose the letter?

I want to give two weeks. I really hate my current position and my boss is a turd. He's a numbskull and I want to tell them that I am resigning because I am underpaid, afraid that my job will be taken from me in the near future, and that I don't agree with any of their politics. Should I include any of this? I have been at this job since I was 21 and now I am 33. I don't know if that makes a difference.