Hi Brendan,
The first information you must enter in the mailing list archive page (
http://n2.nabble.com/more/MailingListRequest.jtp) is the email address of your list. The second is the URL (internet address) of the page where people can find more information about your mailing list. For example, see this URL:
http://tech.groups.yahoo.com/group/domaindrivendesign/Your yahoo group certainly has an address like that.
Does that answer your question?
Regards,
Hugo Teixeira
Nabble.com