I highly recommend Basic Economics by Thomas Sowell. The title is not very imaginative but I found it a great place to start before looking at more complicated concepts.
http://www.amazon.com/Basic-Economics-2nd-Ed-Citizens/dp/046...
http://www.amazon.com/Basic-Economics-2nd-Ed-Citizens/dp/046...
http://www.amazon.com/Basic-Economics-3rd-Ed-Economy/dp/0465...
Not the complete book though.