When beginning to study any foreign language, one of the most important things to remember is that you will almost certainly be required to master sounds that do not exist in English. The rolled 'r' of Spanish, the high 'u' of German and French, and the aspirated 't' of Hindi are all sounds that do not have corresponding equivalents in English. Mandarin Chinese is a language that contains many such sounds, and it is especially important to be careful when recognizing and producing these foreign sounds because Mandarin Chinese is a tonal language. This means that a single syllable, such as "bao", can have several different meanings depending on the tone in which it is pronounced. There are four tones in standard Mandarin Chinese.
The first tone is high and flat, with no change in pitch.
包 bao - "to wrap"
The second tone starts low and rises to the top of the vocal range.
薄 bao - "thin"
The third tone starts high, but dips to the bottom of the vocal range, and then comes back to the top.
饱 bao - "full"
The fourth tone starts high and falls sharply.
爆 bao - "explode"
Many foreign learners of Chinese find that recognizing, producing, and especially remembering the correct tone for individual words is one of the most challenging parts of learning the language. While many introductory books seem to overlook this aspect of Chinese, correct tone usage is extremely important in order to be understood. Speaking Chinese without proper tone is akin to speaking English with only one vowel. While context and word order may occasionally allow you to make yourself understood, without a solid command of the four tones even a modest fluency with the language will continue to elude you.
In my book Chinese through Tone and Color, I have assigned a color to each of the four tones to assist the learner in accurately and consistently remembering the correct tone for over 100 of the most common words and characters. This mnemonic system has been successfully tested in high school classrooms and even non-visual learners have found that this basic association helps them remember to distinguish between the dozens of homophones in modern Mandarin. The book contains commentary and several example sentences for each major entry as also includes an mp3 CD with images attached to the files for portable learning.
Get a taste for what's in the book here.