This is most popular Islamic text book used in the English speaking world for the past decade. It is now in two parts:

Part One teaches about:

Aqeedah

Fiqh

Islamic manners and morals

Seerah

Part Two teaches about:

Men and women around the Prophet Muhammad

Stories of the prophets

Supplications and invocations

Hadiths

This is a great Islamic book for kids. It is one of the books that is important for learning about Islam.