Oh, yes! A vibrant trans-Saharan trade is one of the characteristics of the medieval world economy--salt, gold, ivory. By the high Middle Ages, West Africa was very much part of the circum-Mediterranean world (and with a gradual, willing conversion to Islam to show for it!). North African Muslims in particular wrote rather a lot about the Sahara, its people, and the kingdoms of Ghana and Mali.

In English, you can read:

• Levtzion & Hopkins (trans. and ed.), Corpus of Early Arabic Sources for West African History, which is what it says on the tin
• Levtzion & Spaulding (trans. and ed.),Medieval West Africa: Views from Arab Scholars and Merchants, which is selections from the above

For a lot of modern readers, the most intriguing writers are Ibn Battuta and al-'Umari. Ibn Battuta was a 14th century traveler whose book includes a firsthand account of his visit to the Mali royal court.

Al-'Umari was an Egyptian official (also in 14C) who never went to Mali himself, but who records probably the most today-famous tales about the kingdom (second or third or fourthhand, one must keep in mind). One involves a Malian mansa (sultan/ruler...mansa) who believed in a land beyond the Atlantic, and launched a massive exploration party with himself at the head. (Of course they were never seen again.) The other is the most famous mansa, Musa, who (supposedly) single-handedly crashed the Mediterranean economy by distributing so much gold during his hajj.

I really, really recommend reading the sources for yourself. Either one of the books, really: I was given Corpus as a gift from a prof and I treasure it; a lot of people would probably consider Medieval West Africa to be "the interesting bits."