I have this book (and studied with its author), and I agree that it's a bit tough to learn from if you don't have a lot of background and/or someone helping you. But it's also kind of an amazing cultural testament.
It's meant to be just the first in a series of five volumes.
It's meant to be just the first in a series of five volumes.
http://thelatinlanguage.org/latinitatis-corpus/