Look at sites such as Yemen Links where you can learn not only the alphabet but also how Arabic is pronounced and written. As there are many links on this site it is best to start with the basic, meaning. the alphabet. Go through it slowly in order to hear how the sounds are pronounced. Practice repeating the sounds in the alphabet a few times. As you practice, remember that Arabic is written and read from left to right.
Check out you YouTube as there are lessons given by Arabic language course Madinah and others that can be watched for free. Choose wisely so that you watch lessons appropriate for your level. Some a good for beginners while others are more appropriate for more advanced students.
Make certain that you are learning the right form of Arabic. Unlike English, which has mainly one form, there are three forms of Arabic: Quranic (Koranic), Modern Standard (or Formal) and Modern Colloquial (or Spoken) Arabic. The Madinah You Tube courses focus on Quranic Arabic, the form used in the Quran and in mosques. The Arabic Online course from the word2word website focuses on Modern Standard Arabic and Formal Arabic. Spoken Arabic is region-specific and generally unwritten, except for in literature, according to Arabic Online author, Hani Deek.
Learn the symbols and pronunciation of the various vowel sounds. In Arabic vowels are used to link letters to make words, as in English. However, unlike in English, symbols are used to add a vowel sound to a consonant. For instance, a small slash to the upper left of a letter, called the fatha, changes the Arabic letter "j" to a "ju," where the vowel has a short "u" sound as in the word jug.
Practice writing the words. According to the Madinah Arabic website and Yemenlinks.com, there is a difference between writing words and writing individual letters in Arabic. The appearance of the letters change depending on whether they are at the beginning, middle or end of the word. Understanding this makes it easier to learn the language as you will be less confused when presented with a unique form of a letter in a word. Note that both sites graphically illustrates the difference between the individual and word forms of a letter.
Learn the grammar. In Arabic, there is no "is." Beside this, there are genders, declensions (word endings) and conjugations which are important to learn when writing and speaking Arabic properly.
Remember to say the words as you write them, no matter if you are learning the grammar or the alphabet or another part of the language. In order to adequately learn to speak Arabic it is important to visualize the language as you use it. This will help you internalize what you learn which aids in retention and better understanding how the language works. All this lends itself to ultimately being able to communicate to a native speaker with ease.