1. the principles of economics. in this period you should cultivate your interest in economics, know some simple principles of economics such as maximazation utility and consumers' choice. This stage you can choose Mankiw, the principles of economics.
2. the intermediate economics. In this stage, learn the mathematical treatment of the principles of all the theories you learned in the first period, know the connections between the real world and abstracted models of economics. This stage, you may choose Varian's for micro and Mankiw or Dornbusch for macro.
3. the advanced stage. You can then try to know the advances in economics and all the models and the critics for them, to formly form you economic mind. I know little about this stage for I am undergradute..
Good Luck!
P.S. I am in korea, using the library computers without chinese keyboard...you may contact me by email if you would like!!