Pinyin Intro — 拼音简介

Learn the simplest PInyin Initial chart.

Learn the simplest Pinyin Final chart.

Learning Exceptions in Pinyin Pronunciation —zhi, chi, shi, ri, zi, ci, si: 

When the seven specific initial consonants (zh, ch, sh, r, z, c, and s) form syllables with the vowel "i," the "i" can be treated as silent.

Learning Exceptions in Pinyin Pronunciation — the special pronunciation of "u" , "ue", "uan" and "un" when they follow the inititals "j", "q", "x", and "y".  

Keep in mind that the "u" here is pronounced as "ü", just as the umlaut.