Yom Kippur is a day (and night – the holiday starts at night and ends on Monday about an hour after sundown) of fasting and prayer. Our congregation Etz Ahaim is Sephardi, and the liturgy is different from that of the Ashkenazi synagogues that my husband and I experienced in our childhoods. The “piyut” or poem that stands out most in my head is Oked Vahanekad (which is for Rosh Hashana). I couldn’t find a good source on the piyutim of Yom Kippur, but here is a link to piyutim of the High Holidays in general with some mp3s available to listen.
It is customary to ask forgiveness of others before Yom Kippur, so if I have done or said anything to offend you, please forgive me.