Firstly my apologies, I'm a total noob, and have just learnt about SQL.

I am running the following SQL:
SELECT COUNT(U.Username)AS NumberOfUsers
FROM Users U
INNER JOIN UserRoles UR on U.Userid = UR.Userid
INNER JOIN Roles R on UR.Roleid = R.Roleid
INNER JOIN Aspnet_users AU on U.Username = AU.Username
INNER JOIN Aspnet_membership AM on AU.Userid = AM.Userid
WHERE R.Rolename = 'Subscribers'

I also want to do it by state. We use Active Social and there is a profile field in that called 'Region'. I can't figure out the table it's in, I tried writing 'WHERE U.Region= VIC" and AS.Region = VIC but to no avail.

Is there a way to run a report that identifies all the table headings so I can construct SQL queries?