The data is stored in a seperate table for user profile fields and can be pulled up through a query or in the user view page.
To get the fields to show in the signup page change them to either required or optional, but show during registration. This option can be found in the settings of each profile field (look for the drop down about 2/3rds down the page).
As far as getting this data into address labels, all you need to do is run a query for the custom fields to store address and perhaps the username if you plan to use that. You can copy the output into a text file, save it as .csv and use word or any other desktop publishing program to create labels from it.
An example query to fetch 5 userfields, the userid and username:
Code:
SELECT u.username,uf.userid,uf.field2 as address,uf.field3 as city,uf.field4 as state,uf.field5 as zipcode,uf.field6 as country
FROM userfield AS uf
LEFT JOIN user AS u ON(u.userid = uf.userid)
WHERE uf.field2 <> ''
LIMIT 5
This can be run through your AdminCP if you have SQL rights for your admin user. Be sure to add any table prefects before both userfield and user if necessary (user vb_userfield). Change the field numbers to whatever your actual settings are.