These are notes from WenLin software 

MANDARIN SYLLABLES

A Mandarin syllable consists of an initial consonant (if any), a vowel or diphthong (combination of vowels), sometimes a final -n, -ng, or -r, and a tone.

CONSONANTS

The consonants are all pronounced approximately the same as in English, with five major exceptions: c, q, x, z, and zh.

Zh, ch, sh, and r are pronounced with the tongue pulled back, away from the teeth.
J, q, and x are pronounced with the tongue pushed forward, almost touching the teeth.
Be careful to distinguish j from zh, q from ch, and x from sh. J, q, and x are always followed by i as in machine, or by the French u sound (see ü with two dots, below). But zh, ch, and sh are never followed by those vowel sounds; after zh, ch, sh, or r, the letter i sounds like an r, with the tongue pulled back, and u is a regular u as in true.

C, ch, k, p, q, and t are pronounced with a strong puff of air.
Z, zh, g, b, j, and d are pronounced the same as c, ch, k, p, q, and t, respectively, minus the puff of air. Unlike English, they are voiceless; for example, d is more like the t in stew than the d in dew; and b is more like the p in spy than the b in buy. (Mandarin b, d, and g are like Spanish or French p, t, and c. In the Wade system of romanization, unlike pinyin, the sounds b, d, and g are spelled P, T, and K, whereas p, t, and k are spelled P', T', and K', with apostrophes to indicate puffs of air.)

VOWELS AND FINALS

In finals such as -iao and -uan, the i or u is shorter than the following vowel. For example, suàn sounds like swan. Notice the difference between xiān (先 'first'), a single syllable, and Xī'ān (西安 name of a city), two syllables. An apostrophe separates syllables when necessary to avoid confusion.
TONES

Tones are simply variations in pitch over time. While pronouncing each syllable, you control the pitch, to give a pitch "contour" to the syllable. Mandarin has four basic tones: each one is indicated by a tone mark placed over a vowel in a pinyin syllable. If you give a word the wrong tone, you may completely change its meaning!

→ ā 1. High Level: pitch starts high and stays constant.
→ á 2. Rising: pitch starts medium and rises higher.
→ ǎ 3. Dipping: pitch starts medium-low, dips very low, and rises to medium-high.
→ à 4. Falling: pitch starts high and quickly falls to very low.

Although the tone mark is written over a single letter, it applies to the entire syllable. For example, in diào, the pitch falls continuously from the d to the o.

With tones, the important thing is the change in pitch over time. The absolute pitch is not important--everyone's voice is different. Find a comfortable range where the high tone is not too high and where you can reach down low for the dipping tone. It is not necessary to match the exact pitch of the man or woman in Wenlin. You should, however, match the pitch contour.

Tones are not an added-on feature designed for special effects; they are just as much a part of pronunciation as consonants and vowels.