Go get the 'Ranma Lambada' song from somewhere and listen to the names!
(Although some are a little wrong as they are singing the sounds, not
saying them)

*sigh* Now to put my Japaneses classes to use... So difficult not to be
able to just say the words...

Ranma   =       rahhhhn-MAH     -NOT-   RAN-mah
Ranko   =       rahhhhn-KOH

*pikupiku* In Japanese the 'ra' is very short.. 'ran-ma' ('a' as in 'father')
Same for 'ran-ko' both very short, sharp sounds for boy sylables

Akane   =       ah-KAHN-nay     -NOT-   Ah-kane

Have you been listening to the Viz version?
'A-ka-ne' as in 'e' ('father'), 'e' as in 'red' but short and cut off half
way... (all sylables really short)

Nabiki  =       nab-BEE-key     -NOT-   Nah-bickee

'Na-bi-ki' 'a' ('father'), 'i' ('ink') ... Again, all sylables really short

Kasumi  =       kah-SUUU-mee

'ka-su-mi' 'a' ('father'), 'u' ('Sue'), 'i' ('ink') ... again, all sylables
sound like they are cut off. (Japanese sounds aren't held as long as English
ones, generally)

Soun    =       SOON (aproximately) more like SOOOOOun

'so^-un' 'so^' ('torch' - a double lengthened 'o' ('open')) 'un' (like in
that game 'Uno') The 'un' is a short sylable

Genma   =       ghen-MAH        -NOT-   JEN-mah

'gen-ma' 'e' ('pen'), 'a' ('father') Both sylables really short. The 'g' is
hard, like in 'guest'

Nadoka  =       nah-doh-KAH

'Na-do-ka' 'a' ('father'), 'o' ('open') All sylables really short

Shampoo =       sham-pooh (heh heh)
Mousse  =       MOO-se

Take a guess. ^_^

Kunou   =       KOON-no

'Ku-no^' 'u' ('Uno'), 'no^' ('torch' - a double lengthened 'o' ('open'))
Only the first sylable is short

Tatewaki = 'ta-te-wa-ki' 'a' ('father'), 'e' ('pen'), 'i' ('ink') ... Again, 
all sylables really short

Kodachi =       koh-DATCH-eeee

'ko-da-chi' 'o' ('open'), 'a' ('father'), 'chi' ('ch' from 'child' + 'i' from
'ink') ... All sylables really short

Ryouga  =       rie-OHHH-gah

'ryo^-ga' 'ryo^' (There is no English sound the same as 'ry*'... it's like
trying to say 'r' when your mouth is saying 'l' so your tongue is half way
between the two positions for those two sounds... then 'ry' would be like
saying 'lily'/'wrist', a mixture between the two + 'o' ('torch' - double
length of the 'o' ('open') ... BUT you have to mix the 'io' in the two 
words together to make it half 'i' and half 'o'), 'a' ('father') 
The second sylable is short... 'g' is like in 'guest' - hard sound. 'ga' is
a short sylable.

Ukyou   =       YOUK-yo or you-KEE-oh

'u-kyo^' 'u' ('Uno'), 'kyo^' (There isn't really an English sound that I can
find for this... ummm... like in 'ryo^' but 'ki/o^' mixing the 'i' and 'o'
so they sound like one thing, and lengthening the 'o' (as in 'torch')...)

Happosai=       hap-oh-SAI  (sai is pronounced like SIGH)

'happo^-sai' 'a' ('father'), 'ppo^' (*sigh* Another hard one to explain...
'pp' is a glotal stop between the last sylable and this one. It's like you
start to say 'p' straight after 'ha', but you hold it for a moment, then
say the 'po^'... 'po^' ('torch' with a double lengthed 'o' ('open')) And
'ai' as in 'sigh') 'ha' and 'sai' are short sylables

Cologne =       col-ohn

Take another guess. ^_^

Hinako  =       HEE-NAK-oh

'hi-na-ko' 'i' ('ink'), 'a' ('father'), 'o' ('open') All short sylables

Shinosuke=      shin-NOOO-sue-KAY

'shi-no-suke' 'shi' ('sh' like in 'shine' + 'i' ('ink')), 'o' ('open'),
'suke' (more like 'ske' with a half said 'u', not a full sound + 'e' ('pen')
All short sylables

Can't think of any more names, right now...

Kun-chan...