I am learning to read and write Arabic now. It is important as a Muslim to know certain things in Arabic, such as prayer and praise for God (dhikr). I am not downgrading praises in any other language, because we go to God as we are. Although, it is nice to be able to praise him in another language. The best book I have found is "The Arabic Alphabet: How to Read and Write It" by Nicholas Awde and Putros Samano. It's a small book, but it's powerful. I have only sat down with this book 4 times and I am already writing words in Arabic and reading a little. It's kind of funny, because I can read the letters that are typed and I can't understand a thing I am reading. It is like reading a scientific journal on quantum physics without a science degree. You read the words, and you might know what one or two words mean, but you can't make heads or tails of the information in a cohesive body.
Just like learning to ride a bike, it will take practice. I love to write Arabic. I am an artist, so I look at writing Arabic more like drawing. Another really nice book is "Arabic Script." Although this book isn't about learning to read or write, it shows the many different calligraphic fonts of Arabic. It even has great examples of the names of God and phrases in Arabic, such as Basmala (Bismillah) meaning "In the name of God."