naomi,
read thru the "Announcement: Eccie Signature Line Guidelines - Updated" listed above the list of threads in this section (also called "forum").
....
https://eccie.net/announcement.php?f=5
that thread also has "Image Standards" listed.
however, you can go into "User CP" (in the Main Menu section on the left), and go into "Edit Your Details".
there's a section there titled "Home Page URL":
"If you would like to let other visitors to this site know the URL of your own web site, enter it here."
good luck & welcome to eccie.