If a person is motivated to learn economics, he should aspire to progress as far as his interest and ability can take him. As everyone is unique in his interest and ability, a wide range of progress in learning economics will exist among different persons. I think all of us who have devoted some time and effort to learning economics have found at each step that we have been able to learn more readily from some authors rather than others. Progress, then, depends on reading widely to discover the authors who speak most effectively to a person at each step in the process of his learning.
Here are three introductory treatments of economics as a discipline:
David Gordon, An Introduction to Economic Reasoning:
http://library.mises.org/books/David%20Gordon/An%20Introduction%20to%20Economic%20Reasoning.pdf
Robert Murphy, Lessons for the Young Economist:
Shawn Ritenour, Foundations of Economics:
http://www.foundationsofeconomics.com/
If introductory treatments are too advanced, try monographs that focus on a few economics truths:
The classic is Henry Hazlitt, Economics in One Lesson:
http://library.mises.org/books/Henry%20Hazlitt/Economics%20in%20One%20Lesson.pdf
Another is The Incredible Bread Machine: