In my 13 years of teaching English to speakers of other languages, Reading Explorer by National Geographic is the best tool I have discovered to build reading skills.
The image to the left is from China's Taobao. In China, Reading Explorer comes as a set of 6 books divided into levels starting at Foundation and going up to Level 5.
In Hong Kong, the set I bought was just 4 levels - Beginner, Elementary, Intermediate and Advanced. The 4 books contained more or less the same material as the 6 book
