How to get random samples from a table? I don't want repeated records between samples
TABLESAMPLE can't provide the mutually exclusive nature between samples that you need even with its REPEATABLE seed.  So I would consider rolling your own, using something like NTILE.  eg assuming your table has a primary key and you want 10 samples, create a table which contains the sample Id and the primary key of the table.  Use it as a 'master' to create your samples from, then you're guaranteed they will not overlap.  Here's a simple example:

-- Create your sample master table; I'm using a temp table here
-- but you could use a permanent one
SELECT NTILE(10) OVER( ORDER BY NEWID() ) sampleId, yourPrimaryKey
INTO #tmp
FROM dbo.yourTable

-- Create the sample, eg sample 3 of 10
SELECT m.*
FROM dbo.yourTable m
WHERE EXISTS
    (
    SELECT *
    FROM #tmp t
    WHERE t.sampleId = 3
      AND m.yourPrimaryKey = t.yourPrimaryKey
    )