that is fine then...

i already posted my intermediate file (this is what i called signup.php) and it was the one that both a) connected to the database and b) sent the form info on to signup2.php

what you want to do is fine. you need:

1) HTML to get ALL the info your visitors are going to list
2) the PHP script that does:
i) has the form sending sub-routine (as shown in previous post)
ii) has 3 calls using the sub-routine sending the results of to the 3 different signup-forms.
iii) an ending saying "thank you, info submitted" type thing.

That is all there is to it, you have everything you need, you need to find out the names of the fields that the scripts you are sending it to use (just view the source on their pages, if it says name="everyone-username" then the field name is everyone-username, just use everyone-username=$username inside the post line to the everyone.net script (already show this).

Have a try and doing it, once you have tried to make the scripts and sections and if you can't get it to work, post everything you have made and i will try and debug it for you.