Most Salafis actually know nothing about Wahhabism.
For this reason, most Salafis mistakenly believe that the ideas of figures like al-Albani and al-Huwayni are consistent with Wahhabism (despite the fact that al-Albani and al-Huwayni are despised as deviants by actual Wahhabis).
If you want to learn about Wahhabism there are six essential steps.
(1) Systematically read the actual works of Muḥammad ibn ʿAbd al-Wahhab -especially Kitab al-Tawhid, Kashf al-Shubuhat, and Mufid al-Mustafid Fi Kufr Tarik at-Tawhid. These must be read together. For example, you cannot understand Kitab al-Tawhid unless you read the other books.
(2) Read the actual history of the pre-1920s Wahhabi movement as described in Ibn Ghannam's Tarikh Najd, Ibn Bishr's Unwan al-Majd, and especially al-Durar al-Saniyya
(3) Learn the names and opinions of the most important traditional Wahhabi authorities. These include Abdullah ibn Muhammad Aal al-Shaykh (1752-1826), Abd al-Rahman ibn Hasan Aal al-Shaykh (1780-1869), Abdullah Aba Butayn (1780-1865), Hamad ibn Atiq (1813-1884), Abdullah ibn Abd al-Latif Aal al-Shaykh (1848-1920), Sulayman ibn Sihman (1850-1930), Abdallah ibn Bulayhid (1867-1940), Abdullah ibn Hasan ibn Husayn Aal al-Shaykh (1870-1958), and Muhammad ibn Ibrahim Aal al-Shaykh (1893-1969).
(4) Read about the history of the Madkhalis, Haddadis, and Daeshis. All of these movements are directly branching out of Wahhabism. You will also see that the Haddadi movement grows out of the Madkhali movement.
(5) Recognize that actual Wahhabis are defined by their Khariji-like extremism in both takfir and tabdi', and are movements devoted to attacking and destroying the general body of Muslims. Wahhabis have radically different ideas on takfir than traditional Hanbalis (including Ibn Taymiyya). Among other things, it is common among Wahhabis to (1) reject al-udhr bi-l-jahl (2) mandate chain takfir (i.e., they takfir Muslims who refuse to takfir those that Wahhabis consider kafirs (3) mandate chain tabdi' (they consider a Muslim to be an extreme heretic if he does not tabdi' a Muslim that Wahhabis consider an extreme heretic) (4) they hold that acts like prostrating to other than Allah, slaughtering for other than Allah, vowing to other than Allah, and calling (dua) to other than Allah are automatically shirk/kufr akbar without regards to the doer's intentions and beliefs (5) they hold that it is permissible to mass takfir entire Muslim lands and declare jihad against their inhabitant (e.g., the lands of the Ottoman empire).
(6) Recognize that Wahhabis play word games to hide their actual beliefs, especially when it comes to mass takfir (i.e., the question of takfir al-naw' and takfir al-mu'ayyan). So, they will say things like "Group X are kafirs" - but they conceal what they mean by this. For example, they will say that "Hindus are kafirs" and "Ahmadis are kafirs" and "Bahais are kafirs." By this they mean that everyone in the group is a kafir. Then they will say that "Asharis are kafirs", "Maturidis are kafirs", and "Twelver Shia are kafirs." If you ask them what they mean by this, they will conceal their beliefs or start giving contradictory answers. Some will say that "we consider the group in general to be kafirs but do not pronounce takfir on individuals from the group because they are excused for ignorance." But others either remain silent or claim that some or all individuals in the group are kafirs. This is because they reject al-udhr bi-l-jahl or strongly restrict its application.
