This is a great text book, and you really will learn to read New Testament Greek in very short order, by working through it diligently, a little each day. I found this was a good text to teach a twelve year old boy from as well. The look on his face when, within a few hours of study, he was translating a passage from the New Testament, was priceless! It starts of "experientially", you listen and learn while you read. Grammar is introduced later. This man, as well as being a Greek scholar, has really studied the fine art of how to teach, and I'm currently enjoying his Hebrew primer, which is just as good.
If you know no, or little Greek, and simply want to read the NT, then this is the book for you. When you've finished you'll be able to read the NT, with the help of a lexicon... and if you want to go on to study classical or modern Greek you'll have made a good start.
Probably the best text book I've ever seen on Koine Greek.