Try this:
DECLARE @tmp TABLE(MonthCol DATE, [NoProjects] INT, [Amount] INT, [Ab_Zugang] VARCHAR(30))
INSERT INTO @tmp
VALUES('2014-05-01' , 8 , 3004 , 'Abgang'),
('2014-02-01' , 5 , 2314 , 'Abgang'),
('2014-11-01' , 10 , 1366 , 'Zugang'),
('2014-01-01' , 1 , 37443 , 'Zugang'),
('2014-07-01' , 7 , 18400 , 'Zugang'),
('2014-12-01' , 3 , 1500 , 'Abgang'),
('2014-06-01' , 11 , 2000 , 'Zugang'),
('2014-09-01' , 9 , 8000 , 'Zugang'),
('2014-03-01' , 5 , 2555 , 'Zugang'),
('2014-01-01' , 2 , 5000 , 'Zugang'),
('2014-03-01' , 7 , 7000 , 'Zugang')
SELECT [Month_Quarter] AS [Quarter], COALESCE(SUM([Zugang]),0) Zugang, SUM([ZugangAmount]) [ZugangAmount], COALESCE(SUM([Abgang]),0) Abgang, SUM([AbgangAmount]) [AbgangAmount]
FROM
(
SELECT 'Q'+CONVERT(VARCHAR(5), DATEPART(QUARTER,MonthCol)) [Month_Quarter],
CASE WHEN Ab_Zugang = 'Zugang' THEN COUNT(NoProjects) ELSE 0 END AS [Zugang],
CASE WHEN Ab_Zugang = 'Zugang' THEN SUM([Amount]) ELSE 0 END AS [ZugangAmount],
CASE WHEN Ab_Zugang = 'Abgang' THEN COUNT(NoProjects) ELSE 0 END AS [Abgang],
CASE WHEN Ab_Zugang = 'Abgang' THEN SUM([Amount]) ELSE 0 END AS [AbgangAmount]
FROM @tmp
GROUP BY DATEPART(QUARTER,MonthCol), Ab_Zugang
) dt
GROUP BY [Month_Quarter]
Result:
Quarter Zugang ZugangAmount Abgang AbgangAmount
Q1 4 51998 1 2314
Q2 1 2000 1 3004
Q3 2 26400 0 0
Q4 1 1366 1 1500
[EDIT]
The same result you can achieve by joining two pivots:
SELECT t1.[Quarter], t1.Zugang, t2.Zugang AS [ZugangAmount], t1.Abgang, t2.Abgang AS [AbgangAmount]
FROM(
SELECT [Quarter], [Abgang], [Zugang]
FROM
(
SELECT 'Q'+CONVERT(VARCHAR(5), DATEPART(QUARTER,MonthCol)) [Quarter], [Ab_Zugang], NoProjects
FROM @tmp
) dt1
PIVOT(COUNT(NoProjects) FOR [Ab_Zugang] IN ([Abgang], [Zugang])) AS pvt1
) AS t1 INNER JOIN
(
SELECT [Quarter], [Abgang], [Zugang]
FROM (
SELECT 'Q'+CONVERT(VARCHAR(5), DATEPART(QUARTER,MonthCol)) AS [Quarter], [Ab_Zugang], [Amount]
FROM @tmp
) dt2
PIVOT(SUM([Amount]) FOR [Ab_Zugang] IN ([Abgang], [Zugang])) pvt2
) AS t2 ON t1.[Quarter] = t2.[Quarter]