Is it better for a student of Islamic knowledge to begin by memorizing the Qur’an, understanding its meanings and the rules of Tajweed, and then move on to other sciences, or to combine memorizing the Qur’an with studying some simplified books in other Islamic sciences?

The best thing for a student of knowledge to focus on is the Noble Qur’an: memorizing it, reciting it with proper tajwid, and understanding its interpretation. "The best among you is he who learns the Qur’an and teaches it." It is preferable to begin memorizing the Qur’an for a boy before the age of responsibility, as Imam Ahmad stated. As for an adult, he should begin with the essential sciences upon which the correctness of his worship depends, after mastering Al-Fatihah and what suffices from the Qur’an for the validity of prayer.