If you have sucessfully learned either as a second language and can speak it fluently, what do you suggest? I don't know Hebrew at all, but I do speak some Arabic. I started by picking up some words from my husband, but it was all silly stuff like "crazy", "donkey", insults about people's mothers... so I took a college Arabic course. It was so helpful learning how to read and write arabic script and the arabic alphabet because I understood the phonemic significance in the language. But learning in a classroom is not the place for me! Living with a Moroccan family for three weeks strenghted my Arabic significantly (though it's a different dialect than what's spoken by Palestinians), I wish I could have stayed with them longer. Linguistics say it takes about two years of immersed participant observation to become fluent in a language.
For a beginner Arabic speaker, I think this audiobook will be a real help (it helped me!); you can buy it on iTunes for $11 USD.
http://www.earwormslearning.com/pdf/Booklet_Arabic.pdf
So, what to you think? Classroom learning, self-learning, or full immersion? I think a combination of all three is the best way to learn. :)