This is not a complete Arabic language course, but it is built upon the same learning strategy used in Western universities. By the time you reach lesson 18, you will not have covered more than 3 weeks of such studies. By then you should see whether you want to continue learning more or not.
There are several specialized books to choose from, if you would like to continue. We hope that the combination of sound, writing and grammar here in BABEL:arabic will make your move into such books an easy one.
Before continuing, just consider that there are different Arabics to select from. Modern Standard Arabic, which you have seen here, is great for anyone going for a literary understanding of the language, it be books or newspapers.
Should communication skills be most important to you, this is the time to rather choose one of the local variations for Arabic. By far the most versatile is Cairo Arabic, simply for being understood from the many movies and TV-series distributed to all Arabic countries. A version of Arabic close to Modern Standard Arabic, is Damascus Arabic. This is also widely understood around the Arabic world, simply from containing familiar words and expressions. Other people may not be able to adjust their Arabic so easily to Damascus Arabic as to Cairo Arabic, making conversations more difficult here.