Why do I suggest learning BoPoMo, rather than using English alphabet pronunciation or Pin-yin?
Many people asked me why we still teach beginners to learn BoPoMo, a form of phonetic symbols. If your goal of learning Chinese is for communicating with Chinese people from Taiwan and China, you may want to sound right to them to understand. There are 37 symbols which represent 21 consonants and 16 vowels individually, compared with 26 English alphabets. Therefore, Chinese pronunciation cannot be totally replaced by using English alphabets. Besides, learning to recognize BoPoMo, Chinese phonetic symbols, which were designed by taking from the parts of Chinese characters, will help you write Chinese characters easily.
Another reason is that using English alphabets to learn Chinese may confuse the younger kids who learn both English and Chinese at the same time.
Once you learn how to sound each Chinese phonetic symbol and know how to combine them, you will find it so easy to speak Chinese by reading Chinese phonetic symbols. It's because one Chinese word has one pronunciation by combining only two or three at most phonetic symbols together.
However, after you get familiar with BoPoMo, you can easily learn Pin-yin to type on computer. Refer to the table for BoPoMo and Pin-yin. But don't just satisfy with typing Chinese in Pin-yin. Learning Chinese characters is the most artistic training.