Want To Sell

Hello. I have written a self-published book. The book was released last October. The books are physically stored at my house. I primarily sell the book through my website and at book presentations, signings and events. I handle and ship the books myself (USPS media mail). I have roughly 500 units left and would possibly like to sell on amazon. What plan should I use? (I would not plan on selling more than 40 per month) All I need to do is post the book on amazon. I will ship the book from my residence. What fees are involved to do this? Look forward to your response