Mukhtārāt min Mu'alafāt Shaykh Uthman ibn Fodiyo [Selected Writings of Shaykh Uthman Dan Fodiyo] 
 
This is a 3 volume collection of books authored by none other than Shehu Uthman Dan Fodiyo (may Allah envelop him in His Mercy - Ameen). It contains 43 Arabic books on a wide variety of subjects such as 'Aqeedah (belief), Fiqh (outward practice), Tasawwuf (spirituality), government, marriage, bid'ah (blameworthy innovations) and more.