Is there any recommended books on grammar or anything? What would be your recommended way of studying this language?
I have 'Hawaiian Grammar' by Elbert & Pukui (ISBN 082482489X). It is a scholarly reference grammar that is highly praised. I can't honestly rave about, but it isn't horrible, either. It is the only such grammar I have seen for Hawaiian (Not that I've done that deep of a search). I prefer it to Elbert's dictionary, which I find annoyingly hard to use. For a textbook, I like 'Ka Lei Ha'aheo: Beginning Hawaiian' by Hopkins (ISBN 082481259X). The Duolingo course is okay, but very skimpy & there isn't much in the way of audio yet.