Human Capital -- The Lucas-Uzawa Model
    The standard model of suatined long-run growth driven by the accumulation of human capital is the Lucas-Uzawa model, especially in the form made popular by Lucas (1988). 
Required Reading

Lucas, Robert E. (1990): "Why Doesn't Capital Flow from Rich to Poor Countries?" American Economic Review, Papers and Proceedings, 80(2): 92-96.

Lucas, Robert E. (1988): "On the Mechanics of Economic Development." Journal of Monetary Economics, 22:3-42.
Further Reading

Uzawa, Hirofumi (1965): "Optimum Technical Change in an Aggregative Model of Economic Growth." International Economic Review, 6:18-31.

Helpman, Elhanan and Antonio Rangel (1999): "Adjustment to a new technology: Experience and training." Journal of Economic Growth,4(4):359-384.