The Mzungu Boy by Meja Mwangi

Kariuki knows the land around his African village well -- the forest, the rivers, the grassy plateu where Zebra, Gazelles and Wildebeasts live. Thats where he and his new freind Nigel go hunting for Old Moses, the ugliest, oldest and meanest warthog in the whole world.

But it turns out that Old Moses is not the biggest danger that awaits the two boys. There are dangerous men in the forest, and Nigel is the mzungu boy, the grandson of the ruthless and powerfull local  landowner.

A story about freindship and adventure set in Kenya before independance, at a time when people were rising up against British rule.