Bio: Learning Japanese and now able to read programming, business and general how-to books and communicate via email using Kanji. Reading literature with its flowery vocabulary and Kanji though is still very hard. Can write under 1500 - 2000 Kanji and know nearly a pronunciation for each symbol though there are many many more and far from fluent. I've also started to do some basic translation (Japanese to English) and helping out at Japans Annual Ruby Conference this year with translation. About 5 years in.

From personal experience:

The biggest factor in how fast you improve during your studies is environment. Noticed I said during your studies. Simply being immersed isn't good enough. To create your environment you can (in order of effectiveness):

Find a boy/girlfriend who natively speaks the language. Its best if they cant speak yours. This is steroids for your language learning.

Failing that find roomates - the more the better. Nearly as good.

It doesn't matter if your stuck in your home country - I've met Japanese people who rock at English just because they either had a lazy English speaking partner who couldn't be bothered to learn the lingo or likewise lazy roommates.

Start reading websites, magazines, listening to music and watching films or youtube all in your target language. Pursue your interests as much as possible using your new language. If you like hip-hop then listen to underground hip-hop artists via youtube. Grab their lyrics from the net and translate. Sing it out-load in the shower.

Skype for discussions, Lang8.com for writing blogs and peer review etc etc etc

If your looking at becoming very conversational (talk about wide range of subjects comfortably but not yet bling bling) then its going to be 3 years plus. With that in mind you have to be a well oiled machine with vocabulary management, just being 10% more efficient with your vocabulary means a saving of 3-4 months and compared to the traditional use of lists on paper, software such as Anki helps you be at least 20% more efficient.

Assuming your in this for the long haul, don't neglect the reading and writing part for languages with scripts or "funny" symbols. Rather prioritize it since being able to read books and magazines will help you grasp how things are said naturally. You'll meet new words everyday and come across them time and time again in context helping you internalize them faster. Unlike conversation, you control the pace when reading and its more comfortable for beginners and intermediates. I tried learning Kanji the way native Japanese people do and failed miserably. I tried some books most crap but one gem called "Remembering the Kanji" was absolutely amazing. In 2months I got through 2000kanji and by 6 could draw every single one from memory. And there were faster learners than me! I'm sure there's something for Arabic script if that's tricky.

Get the basic tools. Get a learners dictionary to start. Once you start getting better, try an Arabic dictionary for Arabic kids i.e. no English written whatsoever. Ideal would be a dictionary for the pc to aid faster lookups via copy and paste. Don't by cheap crap though as it will probably have awful explanations and old fashioned examples ending up in you sounding like someones granddad.
Likewise look for a good grammar reference.

Get a dictionary plugin for Firefox. I use rikaichan for Japanese. I simply hover over a word and the definition pops up instantly. Very handy.

Lastly implement all of the above slowly one by one, remember Rome wasn't built in a day and have fun.

Hope that helps and good luck.