A good starting point, as the previous reviewer says, which works from a top-down point of view, i.e. stripping away parts to its bare minimum as opposed to starting with the minimum and building it up. This would make a lot of sense from a learners perspective, especially, perhaps, as some learners tend to come into this subject with some form of knowledge. This book helps to clarify the latter.
Succint and to the point - a good book to bein with in this field.