My little brother wants to set up a SWC account, however he doesn't own any
vaild email addresses to join (too young). So I'm offering him to use my
ISP account to join (the same one I'm using). My question comes at
this point in the rules page.
"you must register all accounts by sending the handles to register to email@example.com - this includes handles and the email addresses of all players using the computer."
Do I need register both our accounts before he joins or do I wait untill after?
Also do we both need to send to register or just me?
You shouldn't actually need to send an e-mail, since there is a Multi field in the join form. Assuming he fills that out, after his account is approved you can check your Account Settings to be sure you appear as a registered multi. If you do not, then either of you can e-mail firstname.lastname@example.org to be added manually.