Arabic has many fonts, so you don't have to learn calligraphy. It's enough to memorize the alphabet and learn how to write it correctly. Learning Arabic in English letters and numbers is possible, but it's not a good choice, in my opinion. Reading Arabic written in English letters isn't easy as you may think. Because if you write in Arabic letters, each word has a fixed spelling, but in English letters you'll find the same word written using different spelling. I think it's difficult to memorize the words in this way.

learn by practice , start here http://abubasil.sbilya.com/letters.swf then use virtual Arabic keyboard (available in google translation). postponed hand writing at this level.

As Mohamed and Misaki say, there is no need to learn the other fonts. Just focus on the typical one, it's very easy. But I don't prefer to use the Latin letters to write Arabic. Everything will be easy by practicing. :)

Arabic is a great and ancient language / But its difficult for Foreign /Its my language