Assuming the table contains multiple rows per month you could write a query like this to summarize three months of data.
SELECT Mnth = CONVERT(CHAR(3), datefield, 7), counthits = SUM(counthits)
FROM Tablename
WHERE datefield >= DATEADD(mm, -2, DATEADD(mm, DATEDIFF(mm,0,getdate()), 0))
GROUP BY...