Books for Learning the Creed of Tawhid

Question: Through my following of the program "Nur 'ala al-Darb" on the radio, it became clear to me that we had been practicing many things, all of which were wrong, according to what we had learned through taqlid (following a scholar without knowing his evidence) and imitation of those before us. This is because the religion has been mixed with some impurities that the conscious mind does not accept. There are many bid'ah (religious innovation) and superstitions that have been attached to the religion, though they are not part of it. Praise be to Allah, who has made this program a good guide for us to clarify the correct path, namely the correct knowledge of tawhid (the oneness of Allah), which every believer should arm himself with, and through which he can break down the barriers of superstitions and bid'ah. I hope, with thanks, that you will guide me to the best books on tawhid, and all books that combat bid'ah and superstitions, so that I can obtain them at whatever cost, so that I can combat those bid'ah, by the permission of Allah, with decisive argument and Qur'anic evidence, or from the Prophetic hadith. May Allah reward you with the best reward?

Answer: Praise be to Allah, who has bestowed upon you the knowledge of the truth and the right, and we ask Him to increase you in knowledge and fiqh (Islamic jurisprudence) in His religion, and to keep us and you firm upon the truth.
As for the books that teach the creed of tawhid, they are, by the praise of Allah, numerous and accessible.And among them:
The book "Fath al-Mujid", an explanation of the Book of Tawhid, by the Shaykh 'Abd al-Rahman ibn Hasan (may Allah have mercy on him).

And among them: "The Three Fundamental Principles" and "Kashf al-Shubuhat", both of which are treatises by the Shaykh Muhammad ibn 'Abd al-Wahhab.

And I advise you to acquire the collection: "Tawhid al-Najdiyyah", because it contains concise treatises on tawhid and creed that are beneficial. So you should acquire this blessed collection.
Also "Sharh al-Tahawiyyah", by al-'Izz ibn 'Abi al-'Izz al-Hanafi, which is a beneficial and simplified explanation, and comprehensive of the chapters of creed.

And also the book: "Ighathat al-Lahfan min Masayid al-Shaytan", by the Imam Ibn al-Qayyim. It is a beneficial book regarding matters of creed and warning against bid'ah and deviations. It is a precious book, and it is not befitting for a student of knowledge to be ignorant of it. This is what pertains specifically to creed.
As for what pertains to forbidding bid'ah and warning against it, there are beneficial and accessible books, praise be to Allah.They are:

First: "Iqtida' al-Sirat al-Mustaqim Mukhalafat Ahl al-Jahim," by Shaykh al-Islam Ibn Taymiyyah.

Second: "Al-I'tisam," by the Imam al-Shatibi (may Allah have mercy on him).

Third: The book: "Al-Hawa'idd wa al-Bid'ah", by the Imam al-Tabari.

Fourth: "Al-Bid'ah wa al-Nahy 'Anha," by Ibn Wadhih.

Fifth: "Al-Ba'ith 'ala Inkar al-Bid'ah wa al-Hawa'idd," by the Imam Abu Shama.

Sixth: "Al-Ibda' fi Mudarrat al-Ibtida'", by the Shaykh 'Ali Mahfuz.

Seventh: "Al-Sunnah wa al-Mubtada'at," by the Shaykh Muhammad 'Abd al-Salam Khadr.

Eighth: "Al-Tahdhir min al-Bid'ah," by the Shaykh 'Abd al-'Aziz ibn Baz.
These are accessible books; some are distributed for free, and some for a small price. You should acquire them, or acquire whatever is available of them, and in them is good, if Allah wills.
However, I advise you and those like you not to limit yourselves to reading books. You must seek out reliable scholars of knowledge to read these books with, so that they can explain to you the obscure parts and clarify to you the truth contained in them. And Allah is the One who grants success.