Ok, the first think you need to do is make sure you are a member of the site. This means that one of the owners of the site has added you to the list. Send a message to email@example.com or DERREL@FINCHER.COM and asked to be joined to the the AERA AR SIG. If you have more than one email address, send us the one you use with google tools or send all of the ones you want to use. If you received a message saying your a member, then you just have to sign in both the sign in and sign up with google are in a link at the footer of every page on the far left.
You don't have to have a gmail account, but you do have to verify your address with google. (Google needs this to keep us safe from spammers.)
This short video will help you either sign in or register a email account:
AERA AR SIG Help