Hi, I want to sell some of my textbooks on Amazon.com

I need to know, what kind of mailers do I need? I know they are media mailers but I’m not sure which one to purchase

Please let me know and provide links if possible, also, if any of these mailers are available at the Post Office or Office Depot please tell me

Thanks!

I have used textbooks and I have seen people posting their used textbooks on amazon.com before. Is this free to do? And does amazon take a part of the profit? Please help! thanks