The advice I can offer you is this:
If you really want to learn a language so you can become what I call 'fluid' (not fluent, i.e. if you were going to an arabic speaking country on holiday you'd be able to get by). Then the easiest way is to actually go for an extended period of time (at least a month) to a place where the language is spoken, and make sure you aren't around any English speakers. You will gain confidence, the ability to understand and be understood BUT your written arabic and grammar will not be that good.
If you want to learn a language properly, grammar and all, you need to go to classes every week. IMO you cannot just teach yourself a language, particularly if you don't already speak other languages and don't have the experience of learning before.
I would recommend getting the Pimsleur courses - 'listen and repeat' does work well, and also having lessons for six months, and then going to say, Egypt, for a month next year....
