This introductory article from Chabad.org provides a brief overview of the mitzvot and rituals performed on the day before Yom Kippur, according to Orthodox custom, including the kaparot atonement ritual, making amends with people we may have hurt or been hurt by, and partaking in the pre-fast meal. With internal links to relevant texts, how-to guides, and articles, this is a great resource for those looking for how to prepare for the holiest day on the Jewish calendar.