If you know Japanese, you can help too!
If you see any mistakes, feel free to jump in and correct it.
To begin with, I'll put a pronunciation key to learn. Unlike Chinese, Japanese uses katakana and hiragana to express pronunciations. Likewise will I in this thread.
So...
Hiragana is the Japanese script that spells out native Japanese words or aids people in reading kanji (Chinese characters), which appears as furigana above a character.
Katakana is the Japanese script that spells out foreign words and names or new Japanese words like "ka-ra-o-ke" and "pa-chi-n-ko".
Hiragana = red
Katakana = blue
Romaji = purple
Vowels
あ ア A "Ah" as in "watt"
い イ I "Ee" as in "teeth"
う ウ U "Oo" as in "good"
え エ E "Eh" as in "pet"
お オ O "O" as in "more" (not as "oh" sounding as "toe")
"K" consonants
か カ KA Like the "co" in "cob"
き キ KI Like "key" as in "key"
く ク KU Like the "coo" in "cook" (not as "coo" as the word "coo")
け ケ KE Like the"ca" in "care" (not as "kay" as the in word "came")
こ コ KO Like "co" in "core" (not as "oh" sounding as "cold")
"S" consonants
さ サ SA Like the "so" in "sob"
し シ SHI Like the "she" in "she"
す ス SU Like the"su" in "surprise" (Not as strong as in the word "sue")
せ セ SE Like the "seh" in "second" (not as strong as in the word "say")
そ ソ SO Like "so" in "song" (not as "oh" sounding as the word "so")
"T" consonants
たタTA Like the "to" in "top"
ちチCHI Like "chee" as in "cheese"
つツ TSU Like the"tsu" in "tsunami"
てテTE Like the "te" in "text" (Not as "ay" as in "tape")
とト TO Like "to" in "tomato" (not as "oh" sounding as "toes")
"N" consonants
なナNA Like the "no" in "knob"
にニNI Like "nee" as in "knee"
ぬヌNU Like the "ne" in "nerd" (Not as "oo" as in the word "new")
ねネ NE Like the"ne" in "net" (Not as "ay" as in the word "nay")
のノ NO Like "no" in "nor" (not as "oh" sounding as the word"no")
"H" consonants
はハHA/WA Like "ha" in laughter at the beginning of a sentence, like "wa" when used as a marker
ひヒHI Like the word "he", sometimes sounds like a cross between "he" and "she"
ふフFU Like the "fu" in "full"
へヘ HE Like the "hai" in "hair"/ Tends to sound like えmid-sentence
ほホ HO Like "ho" in "home" (not as "oh" sounding as "hold")
"M" consonants
ま マ MA"Ma" as in "mama"
み ミ MI"Me" as in "me"
む ム MU"Mu" as in "murky" (not as "oo" a "moo)
め メ ME"Meh" as in "mesmerize"
も も ME"Mo" as in "more"
"R" consonants
らラRA Similar to saying "la" in "lalala"
りリRI Similar to the surname "Lee"
るルRU Similar to the "lu" in "lure"
れレ RE Similar to the the"leh" in "let"
ろロ RO Similar to "lo" in "lore" (not as "loh" sounding as "low")
"Y" sounds
や ヤ YA "Yah" as in "yacht"
ゆ ユ YU "Yü" as in Chinese "Yü"
よ ヨ YO "Yo" as in "your" (not as "yo" as English "yo")
*Add a consonant ending with "-i" to combine it with "y" sounds to combine them. Ex: き+や = kya, ち+よ = cho, し+や = sha, じ+ゆ = ju
"W" sounds
わ ワ WA "Wa" as in "water"
を ヲ WO Similar to お
"-N" ending
ん ン -N Nasalized like French "-n", similar to "-n" in "croissant"
"G" consonants
が = ga、ぎ = gi、 ぐ = gu、 げ = ge、 ご = go (Just like "K", only with accent marks)
"Z" consonants
ざ=za, [b]じ= ji, ず = zu, ぜ = ze, ぞ = zo (Similar to "S", only shi becomes ji)
"D" consonants
だ = da、ぢ = dji、づ = dzu、 で = de、 ど= do (Similar to "T", only chi becomes dji and tsu becomes dzu)
"B" consonants
ば = ba, び = bi, ぶ = bu, べ = be, ぼ = bo (Just like "H", only with accent marks)
"P' consonants
ぱ = pa, ぴ = pi, ぷ = pu, ぺ = pe, ぽ= po (Just like "B" only with circular stress marks)
*A little tsu "っ" before any consonant indicates stress, it is not pronounced. Example: ひっき = hikki (not "hitsuki"), あった = atta (not "atsuta")
This is a good site to learn how to write the Japanese scripts.
Katakana strokes
Hiragana strokes
Edit: Here are some examples of words in Japanese that use strictly katakana or romaji:
Katakana:
ゲーム geemu = game
コンピューター konpyuutaa = computer
シャツ shatsu = shirt
アメリカ Amerika = America
アニータ Aniita = Anita
Romaji:
ぎっちり gitchiri = tightly
あっさりassari = simply
ぎりぎり giri-giri = barely
ぴちぴち pichi-pichi = lively
-っぱなし -ppanashi = keep -ing, have been -ing
