Add JOIN_DATE to the Select list and a group by:
select JOIN_DATE , count (*) from MEMBERS,dbo.MEMBER_PROFILE
where MEMBER_PROFILE.member_no = members.member_no
AND JOIN_DATE between '07-01-2013 00:01' and '07-31-2013 11:59'
and email <> 'selfbuy_customer@cafepress.com'
and ROOT_FOLDER_NO is not null
and email not like '%bvt.bvt'
GROUP BY JOIN_DATE