Just as Ereb Rosh Hashanah is a time for a person to repent for all his sins, Ereb Shabuot is a time to repent for the specific sin of failing to show proper respect to Torah, and neglecting its study. The holy books teach that on Shabuot we are judged with regard to our dedication to and respect for Torah, and thus on Ereb Shabuot we must reflect upon commitment to learning and repent for not respecting it properly. At all times we should beg Hashem to forgive us for not committing ourselves sufficiently to learning, but this is especially vital on Ereb Shabuot, as we prepare for our judgment.
Moreover, every person should personally involve himself in the Yom Tob preparations. Even if somebody normally does not personally make preparations for Shabbat or holidays, one should make a point of making preparations for Shabuot, such as by shopping and the like. Personal involvement shows respect and honor for the Yom Tob, which celebrates Matan Torah, and it thus serves as a Tikkun (rectification) of the sin of failing to properly respect the Torah. As one makes the preparations he must have in mind that he does so for the purpose of rectifying the sin of "Zilzulah Shel Torah" (neglecting the Torah). Likewise, one should purchase the finest foods and wines for the holiday of Shabuot, without being concerned about the costs entailed. Spending money for the Shabuot celebration is a demonstration of honor for the Torah, and if one does so with the intention of achieving a Tikkun for his neglect of Torah study, then he will be rewarded.
One should make a point on Ereb Shabuot to invite poor people to his home for the Shabuot feast, as the Yom Tob celebration must be shared with the less fortunate. Our Sages teach that one who rejoices and celebrates on the holidays but does not share what he has with the poor is "despised and distanced" by Hashem. G-d visits the poor on Yom Tob, as it were, and if He sees poor people without food for the holiday without others helping them, He gets angry, and this leads to punishment, Heaven forbid. And thus before every holiday, one should ensure to give charity to enable the poor to properly celebrate. On Ereb Shabuot, in particular, there is a custom to set aside 104 coins for charity to be given to needy Torah scholars.
Summary: On Ereb Shabuot, one should repent for failing to properly respect the Torah and devoting enough time to its study. As part of this process of repentance, one should personally involve himself in the Yom Tob preparations, and spend money for the finest foods and beverages, thus giving honor to the Torah. One must give charity to the poor before Shabuot to enable them to celebrate the Yom Tob.
