Ayat al-Kursi is verse 255 of Surah al-Baqarah, which magnifies Allah's absolute life, sovereignty, and knowledge and affirms that His Kursi encompasses the heavens and the earth. The Prophet (peace be upon him) asked Ubayy ibn Ka'b which verse in the Book of Allah was the greatest, and when Ubayy answered with Ayat al-Kursi the Prophet struck him on the chest and said, "May knowledge be pleasant for you, O Abu al-Mundhir." It is recommended to recite it after every obligatory prayer and when going to sleep, as it contains a comprehensive declaration of Allah's tawhid and majesty.
Informational, not a personal fatwa. Consult a qualified scholar for rulings on your situation.