Japanese Pronunciation

Spoken Japanese consists of simple syllables, generally consisting of a vowel, or a consonant plus a vowel. Japanese is not a tonal language like Chinese or Thai, and is comparatively easy to pronounce. There are few complex consonant clusters and all vowels and consonants have consistent pronunciation.

Consonants
Consonants are crisply pronounced. The consonant sounds are:

• k = as in cat

• g = as in gourd

• s = as in Sue

• sh = as in seashore

• z = as in zoo

• j = as in Jack

• t = as in tick

• ts = this is one of the tricky ones; think tsetse fly.

• ch = as in chicken

• n = as in new

• h = as in have

• f = another slightly tricky one; think of “who” with an f sound

• b = as in Boeing

• p = as in party, pea, Poe

• m = as in mama

• ya = as in yahoo, yeoman,

• r = like 'r' in "row" (actually a sound between 'l' and 'r', but closer to 'r') [2]

• w = as in wander

Notes:

1. Sometimes syllables are made up of a combination of a consonant and a semi-vowel (ya, yu, yo) as in Tōkyō, Kyōto, gyūniku (beef), etc. These are NOT pronounced Tokiyo, Kiyoto, giyuniku. The consonant plus semi-vowel sound should be a single syllable. Think of kyu in the English word “cute.”
2. The pronunciation of the Japanese “R” one is the source of the stereotypical difficulties that some Japanese have with pronouncing “L” and “R”.

Vowels
The Japanese language has only 5 vowels: A, I, U, E, O. They are terse vowels, pronounced clearly and sharply. If there are two or more vowels one after the other, each vowel is pronounced individually.

ex. ai (love) ~ ah ee

If one pronounces the vowels in the following sentence one will have their approximate sounds.

Ah (a), we (i) soon (u) get (e) old (o).

Notes:

1. The "U" is pronounced with no forward movement of the lips.
2. "U" is often weak at the end of syllables. In particular, the common endings "...desu" and "...masu" are pronounced as "des'" and "mas'" respectively.

Source
About.com
Foreign Cultures 84, Tokyo