The Church provides for us a rich selection of readings for each day leading up to Christmas.
One easy and simple way to read the Bible with the intention of preparing for Christmas is to read the readings the Church has selected for daily Mass. It provides a rich source of meditation and takes a person through powerful prophecies of the Old Testament.
For example, many of the First Readings take you on a journey through the book of Isaiah, highlighting all of the passages referencing the coming of the Messiah. As the days draw near to the celebration of Christmas, the passages become more explicit in their prophecy, such as this passage from Isaiah for December 20.
The LORD spoke to Ahaz:
Ask for a sign from the LORD, your God;
let it be deep as the nether world, or high as the sky!
But Ahaz answered,
“I will not ask! I will not tempt the LORD!”
Then Isaiah said:
Listen, O house of David!
Is it not enough for you to weary men,
must you also weary my God?
Therefore the Lord himself will give you this sign:
the virgin shall conceive and bear a son,
and shall name him Emmanuel. (Isaiah 7:10-14)
There are also passages from the prophets Jeremiah, Baruch, and Micah and the wise scribe Sirach. They all build upon each other and culminate in the birth of the Messiah on Christmas day.
If you are looking for a simple way to prepare your heart for Christmas, consider reading the scriptures passages selected by the Church for this purpose. The easiest place to find these readings is on the USCCB website.