Chinese is a difficult language to learn, partially because it is hard to know where to begin! You can use this page as a reference to start your journey. Good luck!
Here's a quick index
In chinese there are 4 tones, with a 5th neutral tone
There are quite a few possible sounds in chinese, the pin1yin1 system, while useful, is highly inaccurate for english speakers. Here's a comprehensive list of how to pronounce chinese sounds