Sending letters overseas question?

Question:

ok so I have a pen pal in Japan and Korea so I was wondering about sending some letters to them.
If I only send a letter how much will it cost?
Do I have to fill out one of those forms that tell what is in the envelope? Like when you send a package.
Also can I just mail it from my mailbox or do I have to go to the post office to drop it off?

thank you if you can help me out.

Answer:

It's 98 cents an ounce for a regular air mail letter. You don't have to fill out any forms if all you send is a letter. If it's just a couple of pages 98 cents worth of stamps should be fine.
If you decide to send a package you would have to fill out a form that states what's inside and it's value.