The Timbuktu Manuscripts have hundreds of thousands of Islamic writings, on a big range of subjects. There is also a large collection in Northern Nigeria, and across parts of West Africa. In the south Nigeria, the Igbo used a script to describe court cases.

In the East, the Ethiopians wrote beautiful illuminated bibles and other books.

In terms of Oral tradition, the Yoruba recorded the Odu Ifa, which was memorised and passed down, apparently from over 2000 years ago.

Source: A History of Nigeria, and a History of the World by Andrew Marr