Quick Question on "Steps to take to file a lawsuit"

Hi,
I have a Quick Question on "Steps to take to file a lawsuit" in the front page
I have filed my complain to district court, and Served the complaint + summons to all defendants and US atty office via CERTIFIED MAIL.
Right now, I got return receipt from US atty office.
I have the question of the following statement
[B]"File the return receipt with the court, and send a copy to the US atty office."[/B]

My question is:
1. Shall I mail the copy of return receipt from US atty office with court or wait all the return receipt from all my defendants?
2. When I send copy to the US atty office, it that means I mail the copy of return receipt from US atty office to US atty office again? Shall I put something else?