This was my textbook for my French course in High School. A very well written book it is deceptively thin for the amount of material in it. It starts off at a gentle curve but within no time its difficulty increases exponentially. However due to a conversational style of teaching the language, at times as dialogues between people in a certain context and at times as essays about various places or events, it is a engaging read.
However this book alone will not be useful for a non French speaking student. This book will have to be complemented with a good French-English dictionary, as well as a competent instructor (without an instructor the book can feel daunting after 1/3 of the way through). The instructor is particularly important if the student wants to learn how to speak the language too.