Even if you are not interested in learning Arabic for religious reasons, a good place to begin is Islam 101. In addition to many resources about the Quran, Islam 101 featured an Arabic letters page with a handy chart of the entire Arabic alphabet. The same basic chart, along with a much expanded one featuring the four kinds ways you can form Arabic letters and a handy Arabic alphabet picture chart suitable for either adults or children, can be found at the website of the Portsmouth Ethnic Minority Achievement Service. Neither one of these pages contain the ability to hear Arabic being spoken, but you can print out the charts for handy reference.
Islamicart has a more complex interactive alphabet chart. Though not especially good for printing, when you pass your mouse over any letter on the chart, a transliteration of the name of that letter appears. If you actually click on the letter, you get a short animation showing you how to write that letter correctly in Arabic script. If you click on a section of the chart called "Information," you get an explanation of the equivalent sound in English, if any.
Much more complex and comprehensive, the Shariah Program offers a free online course in the Arabic Alphabet. There are 21 lessons in the course, covering the basics of the alphabet, vowels, syllables, reading practice, pronunciation, letter combinations and primary and secondary qualities of the letters. The Shariah Program course is packed with information, charts and sound files. Reading practice is all done in script, not English transliteration. The sounds, however, are still in Real Audio format and not MP3.
The Fun With Arabic website takes a lighthearted approach to teaching the Arabic alphabet. Suitable either for beginners or children, Fun With Arabic uses animation, colorful design and quite the catchy song to teach information about the alphabet and basic grammar. You can hear the letters pronounced and take a quiz to test your knowledge. You can also purchase Fun With Arabic's workbook, a step-by-step guide to writing the language. Fun With Arabic also has an excellent links page, with even more places to learn about and practice writing the alphabet.