How can I send a song to my friend?

If the song is copyrighted and you do not have the author's permission, you cannot even have the song, unless you have paid the fee required by the owner of the copyright.

What song and how did you get it? Are you not aware of copyright laws and piracy?

Maybe it's a song that insooklee has written, recorded and would like to send to a friend, and just wants to figure out how to get it into a computer and then learn how to send it?

That would also be a possibility. But, we won't know that until insooklee returns and lets us know.

If it is free song then you can upload it to rapidshare

Just open RapidShare: 1-Click Webhosting , there is a option for upload , browse the song and click OK
It will upload the file to rapidshare server ,it will take some time to upload depending upon your speed , then you will get a link
You can send this link to your friend by email , and your friend can download it by paste
The link on the address bar on web browser for free