Finally got something Working ...

SELECT A.UserID, A.FullName, ISNULL(B.TotalSignups,0) AS TotalSignups, B.Month FROM

(

SELECT UserID, FullName

FROM tblGen_Users

WHERE GroupID = 4

) AS A LEFT OUTER JOIN

(

SELECT SignedByUserID, COUNT(1) AS TotalSignups, DATENAME(Month, SignupDate) AS Month

FROM tblMer_Outlet

WHERE SignupDate BETWEEN '2014-04-01' AND '2014-05-01'

GROUP BY SignedByUserID, DATENAME(Month, SignupDate)

) AS B ON A.UserID = B.SignedByUserID

ORDER BY A.FullName