4 of the 12 stories I had read before (in "The Big Book of Christmas Mysteries"): 'The Christmas Party', 'The Dauphin's Doll', 'Death on Christmas Eve' & 'The Thirteenth Day of Christmas'.

Here are my ratings for the stories:
Christmas Party by Rex Stout (4*)
Do Your Christmas Shoplifting Early by Robert Somerlott (4*)
The Necklace of Pearls by Dorothy L. Sayers (3.5*)
Father Crumlish Celebrates Christmas by Alice Scanlan Reach (3.5*)
The Christmas Masque by S. S. Rafferty (3*)
The Dauphin's Doll by Ellery Queen (4*)
By the Chimney with Care by Nick O'Donohoe (3.5*)
The Problem of the Christmas Steeple by Edward D. Hoch (4*)
Death on Christmas Eve by Stanley Ellin (2*)
The Adventure of the Unique Dickensians by August Derleth (3.5*)
Blind Man's Hood by John Dickson Carr (4*)
and The Thirteenth Day of Christmas by Isaac Asimov (3.5*) ( )