Just a quick share. The madina arabic website has recently undergone a redo and they have added many new features to their site. They have a completely free arabic course, you can print it as an ebook which you can use as text book for home education. Secondly they have a wonderful new (or new to me) vocabulary application where you can learn a lot of new words in different categories with the help of multimedia flash cards, a quiz application to test your Arabic language, and even a mobile vocabulary application so you can learn Arabic on the go.
Secondly, there is a Learn Quranic Arabic channel on youtube. This channel has got tons of videos about the madina arabic books. But their true gem is a series of lessons by none other than Dr Abdur Raheem who is the head of Quran translation at King Fahad Quran printing complex. This lesson is an advanced one (one need to finish the madina arabic books before being able to take this course) but is full of knowledge and very beneficial.