Hunting the Hun in [British] South West Africa by WH Kirby (1915)
Articles on Congo during the War.
The National Army Museum has some articles on the First World War in Africa.
The IWM has an interview available online with Edward Northey’s ADC, William Wynne Honywood, on his time East Africa – reels 3 and 4. An interesting 1916 coin belonging to Honywood was auctioned in 2018.
Australian ship HMS Pioneer and the blockade of German East Africa.
Geoffrey Popplewell who arrived in Tanganyika in 1927 shares his discoveries concerning the war in that theatre.
For those who read German, here is some info on the German Schutztruppe.
Some maps of Africa during the war can be found in the Digital Archive of the McMaster University Library.