I am unfamiliar with "songarea.com" but the reference to "your file" would be the full url/address to the music file to be played.
Example:
http://pirates.teamofx.us/sounds/Spanish_Ladies.mp3
No worries me mod friends.. its strictly instrumental.
Please dont link to that one... its not that good, you likely wont want to anyway
ADDED LATER
I did a little research on your songarea.com.
They do require you to display some ad information, so it may even be blocked by management in the future if it doesnt fit appropriate POF guidelines. I do not review/authorize external hosting sites for POF. My assistance here does not mean that it is or will be an approved external hosting site.
That being said...
There is no need to use the code samples in the aforementioned userpage guides to implement a song from "songarea.com"
Pick a song on songarea.com
Have it generate the code for "HTML" or "OTHER".
Copy/paste the entire code they give you into your userpage where you want the music to be.
Save.... done