Here is a great article on this topic.
Here is a great debate on China's aids to Africa. It is a long 7 parts and full of updated info. The two panelists against China did not debate with facts but had their own agenda (one selling a book).
African countries should control their destinies and learn how to deal with all foreigners. I believe China's economic model is better suited to Africa than the western model as China was at similar stage before. Bill Gates imports the same US agricultural model to Africa which will not be useful when they leave. We need to let them independent for long term as the son of Warren Buffet mentioned. So are the foreign aids that make some African farms bankrupt as they cannot compete with free farm products.
China helps them to build roads in order to extract their mines and oil. Without that, the natural resources will remain unexplored for ever. That is only strategic and it also benefits the majority of Africans. China helps them to fish than giving fishes for their rest of their lives. Contrast to colonization from the west, China helps them to build infrastructure, opera houses, stadiums, hospitals and universities.
As in most of the previous investment from all foreign countries, Chinese make mistakes and hopefully they learn it so they will not repeat the same mistake.
China and Africa should be good trade partners. When there is money available, corruption follows. It happens in most developing countries. Human right is better with better economy in most cases. Hence, China's improving their economies would improve the human rights in theory.
Being a developing country herself, it is not China’s responsibility to fight for the human rights/freedom of their trade partners, but their own citizens’ - did the world learn on foreign intervention from what Bush did to the Middle East?