The Sweet Smell of Christmas by Patricia Scarry
This book was a childhood favorite of mine. I have a tattered and worn copy that lives at my parent's house that my own children look forward to reading each Christmas.
The book follows Bear, as he and his family prepare for Christmas. AND - it's scratch and sniff! Smell an apple pie baking in the oven, hot cocoa on the stove, a fresh pine tree to trim... its a delight to read with little kids.
We paired the book this year with a collection of wooden ornaments to paint (just like the ones on the Bear' family's tree!) You can choose to give the book alone, or add it and some ornaments already gift wrapped and ready to give.