What did the Soviet Union do to spread communism in Africa?

The ideology of Communism held that the world's oppressed masses were divided by artificial distinctions of race, nationality, and culture. These distinctions were either created or reinforced by the capitalist system for its own benefit, and in the process keeping the wretched of the earth in a state of permanent subjection. Given this central tenet of Communism, we can see how the Soviet Union would be a natural ally of the various anti-colonial resistance movements in Africa and elsewhere during the Cold War.
For the most part, these resistance movements were fighting against either Western colonial powers or right-wing dictatorships backed by the United States, so the involvement of the Soviet Union in Africa had an added ideological edge to it. The Soviets supplied arms, funding, and military advisers to groups such as the MPLA in Angola. They also offered substantial support to the ANC in its struggle against apartheid in South Africa.
Propaganda was an important element in the spread of Communism. The Soviets were anxious to portray themselves as the Africans' friends, their comrades in a mutual struggle against capitalist and colonialist oppression. Successive Soviet governments knew that if Communism could be linked in the popular African mind to national liberation, that would make it more likely that the ideology would take root in native soil and subsequently grow. This, after all, is precisely what had happened in China during its war with Japan, and the Soviets were keen to see history repeat itself on the African continent.