Determine which user is assigned to which role

Run this on your target database in Azure (ie: not against the master database)

select m.name as Member, r.name as Role
from sys.database_role_members
inner join sys.database_principals m on sys.database_role_members.member_principal_id = m.principal_id
inner join sys.database_principals r on sys.database_role_members.role_principal_id = r.principal_id
order by m.name

List all the SQL Logins on the SQL Azure Server

SELECT [name], [sid] 
FROM [sys].[sql_logins] 
WHERE [type_desc] = 'SQL_Login'
SELECT [name], [sid]
FROM [sys].[database_principals]
WHERE [type_desc] = 'SQL_USER'