The JACT Reading Greek Course has been written for beginners in the upper school, at university and in adult education. Its aim is to enable students to read fifth- and fourth-century Attic Greek, Homer and Herodotus, with some fluency and intelligence in one to two years. The main medium of learning is a continuous, graded Greek text, adapted from original sources.
An excellent review for those who have some previous experience with ancient Greek. The learning curve is fairly steep, so it's probably not the best text for rock bottom beginners (Athenaze, Mastronarde, or even Hansen & Quinn would be better) but as a review it worked really well for me.
RG focuses on Attic, but the last couple of chapters breeze through Ionic (Herodotus) and Homeric dialects as well. If you are primarily interested in learning New Testament Greek, there are easier ways to go.
The two companion volumes to this one are Reading Greek: Text, which contains the actual readings, and The Independent Study Guide to Reading Greek which contains the answer key for the exercises, the English translations, and many crucial hints. The first two volumes are useless without each other, and the Study Guide is almost indispensable. Get all three if you're going the JACT route.
I really like the fact that Reading Greek gets the student out of paradigm drill and into reading actual texts almost immediately. There really is only one reason to learn Ancient Greek, and that is to read the ancient texts. So getting to the texts on Day One is highly motivating.
My only complaints are 1. Flipping from the reading to the grammar books is a bit cumbersome (couldn't they have combined them into one book, with the reading on one side and the vocabulary on the other?) and 2. The font is too small. My reading vision is good, yet I frequently found myself squinting to make out diacritical marks.
This is an excellent text book for anyone studying Greek especially for the independent student. I had a tutor who recommended it as a study guide and it was very easy to follow the exercises on my own. However, it was helpful for me to have a tutor to check in with at least every couple of weeks with questions. It may be possible to do something like this online at this point.