Format SELECT columns. Alias on left object on right separated by aligned " = ".

e.g.

SELECT
ThisIsMyFirstCol = a.Col1
, SecondCol = a.Col2
, AndTheThrid = a.Col3
, ForthCol = b.Col1
, FithCol = CASE WHEN a.col1 = b.col2 THEN 'A'
WHEN a.col2 = b.col3 THEN 'B' END

FROM dbo.tableA AS a

    INNER JOIN dbo.tableB AS b
        ON a.Col1 = b.Col1