I recently heard it is Shirk to give Christmas presents, but is it also Shirk to accept Christmas presents, I work in a school and receive many presents.

All perfect praise be to Allah, The Lord of the Worlds. I testify that there is none worthy of worship except Allah, and that Muhammad is His slave and Messenger.

It is not Shirk (associating partners to Allah) for a Muslim to offer presents or receive presents at the occasion of Christmas. However, it is forbidden for him to do so (to accept or offer presents on this occasion) because, by doing so, he confirms the falsehood the Christians are upon. This is also considered as helping in falsehood. Allah Says (what means): {Help you one another in virtue, righteousness and piety but do not help one another in sin and transgression.} [Quran 5:2] Ibn Taymiyyah says about the Christian celebrations: 'It is not permissible to attend an uncommon feast that is organized on the occasion of the celebrations of non-Muslims. Similarly, it is not permissible for a Muslim to offer a present (on this occasion) especially, if by doing so, one imitates them, like offering a candle and the like at Christmas.'

Allah knows best.