How to say hello how are you in Chinese?

Ni3 Hao3 - Hello. (you good).

Ni3 hao3 ma1 - How are you, not used that much. Ni3 Hao3 will suffice

The closest transliteration I can give is "nee how" with the tone of your voice scooping down slightly and going up higher ( the third tone, 3).

The character is 你好.