What is Pinyin?

Chinese is not a phonetic language. The pronunciation is not related to the writing of Chinese words (characters). A special tool called Pinyin (pronouncing the sound) is created for people to learn Chinese Mandarin pronunciation. Pinyin is a way to transcribe Chinese characters so people can pronounce it. The writing of Pinyin is similar to English alphabet.
If you listen carefully you will find Chinese is a very beautiful language as it has more musical sounds (vowels) than noise (consonants). Except for nasal sound like "n" and "m", all Chinese syllables ends with vowels. So we call them "Final Sounds". The consonants at the beginning of a syllable are called "Initial Sounds".
Most of Mandarin Chinese sounds are Easy for English speaker to pronounce but some sounds are difficult and require more practice.

Learn the tones

There are four tones. One type of tone is usually over each Chinese word. Each tone type is drawn over the word 'ma' to show the different ways of pronouncing it.
The first tone is a high, flat tone. Your voice stays flat, with no rise or dip in the way it sounds. e.g.
The second tone is a rising tone. Your voice rises when you say this, sort of as if you were asking someone to repeat something by saying "huh?" or "what?"
The third tone is a dipping tone. The way you say the word goes down then up. Such as when you say the letter "B". When two third tone syllables are near each other, the first one retains its third tone sound while the next takes the sound of the fourth tone. Also, unless at the end of a sentence or in the case aforementioned, the third tone just sounds like a second tone starting slightly lower.
The fourth tone is a lowering tone. Just say the whole word as if your voice is becoming more manly, or as if you're reading a book and have come across something new and interesting and are saying "huh". Easy enough? If not, don't fret. It's definitely recommended to hear the tones demonstrated from a native speaker, since it's hard to get an idea of what they sound like purely through text.