Did you get things figured out? If not, try these pages.
The first is a link to the index page - it should say something like "if this is your first visit to cosplay.com, please read the FAQ before your REGISTER". Just click on register, and register a new user.
If that page doesn't show up, this second link is to the beginning of the registration process (I clicked regsiter, then copied the url).
Hope this works!