In Northern Nigeria, many Muslims seek religious instruction to learn about the tenets and practices of their faith. In the “traditional” curriculum (the word “tradition” can be problematic, for example if it implies that systems are static, but I use it as a placeholder sometimes), Muslim children and young adults begin by memorizing part or all of the Qur’an. They typically move next into a series of jurisprudential texts from the Maliki School, one of the four main legal schools in Sunni Islam. The Maliki School is widespread in North and West Africa and takes its name from Imam Malik ibn Anas (d. 795), who lived in Medina and was one of the Successors of the Successors (i.e., the third generation of Muslims).
The Maliki texts that many Northern Nigerian Muslims read are summaries or manuals. They focus on issues like the details of how to perform ablutions before prayer. These texts, in the sequence they are typically read, progress in complexity and length. The first Maliki text in the “traditional” sequence is called Mukhtasar al Akhdari fi al ‘Ibadat ‘ala Madhhab al Imam Malik (Arabic: Akhdari’s Summary of Worship Practices According to the Legal School of Imam Malik). It was authored by Shaykh ‘Abd al Rahman al Akhdari (d. 1585). The text is known as Akhdari for short. The version here (Arabic, .pdf) is 19 pages, which may seem short – fitting for an introductory text, though I hope you will keep in mind that students would typically read this text together with a teacher, and that the text might spur conversations, meaning that the total time to study and master the text might be longer than its page length would lead one to expect.
Akhdari opens with an introductory section on faith and ethical behavior, before moving through the following sections: (a) purity; (b) ablutions with sand; (c) menstruation; (d) childbirth; (e) times of prayer; (f) conditions of prayer; and (g) negligence (i.e., during prayer). Akhdari focuses on prayer, in other words, as a core ritual duty of the individual.
I hope this short treatment of Akhdari has provided some background on what many Northern Nigerian Muslims read. In the media and even in academia, we hear a lot of ideological chatter about what such texts mean – “these texts represent rote memorization and the evils of the ‘madrasa’ system” or “these texts represent a living tradition that evil modernists have scorned.” My aim here is not to engage that ideological chatter, but simply to give you a snapshot into what these kinds of texts are about.
Sahel Blog 
It sounds less focused on Islamic law and more on Islamic culture (if such a broad thing can even be said to exist).
Related but different, what makes up general cultural/political thought among North African Muslims (in general, not assuming that all groups in all North African nations follow the same thought)? Surely there are more modern innovations and takes on philosophy in Islam.
One thing to keep in mind is that Islamic law encompasses not just criminal law but also worship and social relations – so how you pray, purify, etc, is all part of law.
As for more recent texts, what people read depends partly on their interests and affiliations – people might read anything from Sayyid Qutb to Muhammad Iqbal, not to mention a host of contemporary scholars who work in classical molds.