Purchase your materials. It is important that your materials include at least an audio CD and preferably visual aids (such as a DVD) for better instruction. "Al Kitaab" is one such source (see Resources below) that includes both.
Understand the way Arabic is written. The language is written right to left (the opposite of English and European languages) and is always in cursive. There are no "block letters" and no capital letters; instead each letter should flow from one to the next following the rules outlined in your instruction material.
Understand Arabic grammar. Several simple rules, such as a noun is always followed by its adjective, are important to the formation of an Arabic sentence. Additionally, all adjectives must match in number (single, dual, or plural) as well as in gender (about half the words are considered "feminine" and the other half "masculine" and the adjective must match the gender of the noun).
Understand how time and numbers are spoken and written. While the language itself if written right to left, numbers are written left to right (as in English). Similarly, time is told from right to left. Spoken numbers follow the order of size (that is, thousands are spoken of before hundreds, and so on) except for the "tens"--ones are spoken of immediately prior to the tens. For example, in Arabic "15" is said as if it were "5 and 10" and 1985 is said as if it were "one thousand and nine hundred and five and eighty."