Click on 'add a new signup page'.
Here you can select the group or subgroup you want the registrants to be added to, and the options associated with their registration. 'Add as staff' will automatically give the user the author and monitor role.
'Context' will form part of the URL that registrants will need to go to to signup. e.g. a context of 'educ261' will mean a signup URL of http://yourdomain.com/lams/signup/educ261 which will look like this: