There are some obvious things Africa needs that we (the U.S.) can provide or promote. One is flexibility to develop its own strategy for development without the U.S. burdening it with bad conditions, demanding repayment for odious debt, setting the agenda at trade talks and ignoring their needs, and demand they never use compulsory liscensing even in emergency situations like this AIDS pandemic.
We can obviously provide money where it will help, esp. for roads, subsidies to develop indusry, developing health infrastructure, things we like that. We can provide technical advice in developing these plans. We can provide troops or military equiment to end violent conflict if need be.
People are too pessemistic and don't realize how much their fate is tied to Africa's. AIDS has killed 500,000 Americas, about 50x what 9/11 and Iraq have combined. Now that is nothing compared to lack of health insurance or car crashes or saturated fat or smoking, but its worth noting that if we fear terrorists we should fear disease and fear the root causes of terror even more.