The phonetic input method for entering Chinese characters into computers is based on what is called Pinyin, the romanization system for standard Mandarin. Pinyin was approved in 1958 by the government of the People's Republic of China and officially adopted by it in 1979. Since then, the International Organization for Standardization adopted Pinyin as the romanization system for standard Mandarin.
The pronunciation of Chinese characters is also marked with Pinyin.

1. Pinyin Chinese overview

❤ en.Wikipedia: Standard Mandarin

❤ en.Wikipedia: Pinyin

❤ Pinyin.info: Pinyin

❤ en.Wikipedia: Pinyin method

❤ Sinosplice: Pronunciation: Chinese and Japanese

❤ Richard Sears: Chinese etymology

❤ Taiwan romanization (pinyin) and culture

2. Pinyin syllable table

❤ Table of Chinese Pinyin system

❤ University of Maine at Farmington: Table of Pinyin pronunciation (use Opera browser for voice)

❤ Chine-Nouvelle: Table de prononciation du Pinyin

❤ University of Vermont: Table of Chinese phonetics

❤ Chinese Learner: Chinese Pinyin combination chart with Pinyin pronunciation guide

❤ ChinesePod: Pinyin chart with Pinyin pronunciation

❤ QuickMandarin: Chinese Pinyin table with Pinyin pronunciation

❤ input.foruto: 漢語拼音輸入法速查表

3. Online Pinyin Chinese input tool

❤ Pinyin input method for traditional Chinese character 網上拼音輸入法

❤ InputKing: online Chinese input system

❤ Chine-nouvelle: Entrer un texte en Pinyin

❤ Chinese-tools: Pinyin Chinese input method editor

❤ Lexilogos: Clavier chinois, caractères classés par Pinyin

4. Pinyin Chinese IME

❤ 搜狗拼音输入法

❤ 紫光华宇拼音输入法

❤ QQ拼音输入法

❤ 谷歌拼音输入法

❤ Pinyin Joe's Chinese computing help desk

❤ Some of these Pinyin Chinese IMEs also allow to input Chinese character following the stroke order of the character you want to type. For each Chinese character, first type u and then any combination of

        h - 横 heng (horizontal)
        s - 竖 shu  (vertical)
        p - 撇 pie  (left falling)
        n - 捺 na   (right falling)   d - 点 dian (dot)
        z - 折 zhe  (hook)            乙 looks like z

        d and n are equivalent
        

For example with QQ拼音输入法, the stroke order of the Chinese character 音 is

5. Pinyin tool

❤ 谷趣中文 CozyChinese: 2500 common simplified Chinese characters and many tools with voice pronunciation

❤ 汉典: 字典拼音索引, providing voice pronunciation

❤ 在线新华字典: 按拼音进行搜索

❤ Cojak Hanzi dictionary: Unihan Hanzi radical chart

❤ 小马词典: Xiaoma Cidian Chinese/English dictionary

❤ Pin1yin1: Chinese-English dictionary annotated with pronunciation information

❤ Stewart Paton: A Dictionary of Chinese Characters: Accessed by Phonetics (5-Mb PDF file)

❤ Chinese (拼音 Pinyin) collation chart

❤ Country names written in Chinese characters and Pinyin

❤ Learn to write Chinese with animated traditional or simplified character

6. Online Chinese characters to Pinyin converter

❤ 汉字转拼音, simplified Chinese character to Pinyin converter

7. Pinyin e-learning

❤ Cours sur la phonétique chinoise avec l'audio

❤ MIT: Hanyu Pinyin for Mandarin speakers with traditional Chinese character

❤ Pinyin practice with simplified Chinese character

❤ Pinyin pronunciation lab with simplified Chinese character

❤ Chinese pronunciation

❤ Centre for teaching Chinese as a foreign language (UK): Pinyin pronunciation for Mandarin (use Opera browser for voice)

❤ California State University, Long Beach: Conversational Mandarin Chinese online

❤ Harvard University: Chinese pronunciation guide (with RealPlayer)

❤ LanguageGuide.org: 普通话

❤ Confucius institute online: 网络孔子学院

❤ BBC: Real Chinese - Mini-guides - Pinyin

8. Pinyin with Flash

❤ 全部语文拼音

❤ 快乐拼音

9. Pinyin with video

❤ YouTube: How to input Chinese in Windows XP using Pinyin

10. Rota Periodic Table with Pinyin pronunciation