DECLARE @startdate SMALLDATETIME = '2011-01-01'
DECLARE @stopdate SMALLDATETIME = '2011-12-31'

-- Create a Table
DECLARE @weekTable TABLE (
Id INT IDENTITY (1, 1),
StartDate SMALLDATETIME,
EndDate SMALLDATETIME
)

-- Find Monday at that week
DECLARE @currentDate SMALLDATETIME = DATEADD(d, 2 - DATEPART(dw, @startdate), @startdate)

WHILE @currentDate <= @stopdate BEGIN
INSERT INTO @weekTable VALUES (@currentDate, DATEADD(d, 6, @currentDate))
SET @currentDate = DATEADD(ww, 1, @currentDate)
END

-- Return the results
SELECT Id 'Week #', StartDate 'Start Date', EndDate 'End Date'
FROM @weekTable