How to Pronounce Korean

Korean is a bit harder to pronounce for most Westerners than Japanese is.  For
starters, most words aren't fairly monotonous like they are in Japanese--in
other words, they have accented syllables in Korean, while in Japanese, most
words seem to have a fairly flat tone.  As with most languages, the only way
to know how to accent words correctly is to hear someone say it properly.
  Korean is one of the first (if not the first) Asian countries to have a true
alphabet, said to have been invented by the Great King Sejong (Sejong Daewang).
The alphabet (usually called "han'geul" by Koreans, but also sometimes
"joseon'geul") is, like Japanese, written in syllables, but each syllable is
comprised of symbols that denote certain sounds (a consonant, a vowel, and
sometimes, a third consonant).  Hanja (the Korean name for Chinese characters
from the Han dynasty, called "kanji" in Japanese) are rarely used, so it's much
easier for Westerners to learn Korean script than Japanes.
  Here is how to pronounce the different consonants in Korean:

"g" = This is a little difficult for some.  At the beginning of a word or
  phrase, the "g" is actually a "k" sound, without aspiration (that "h" puff of
  air that comes out when an English speaker says a "k").  The muscles of the
  throat, tongue, and palet should remain fairly relaxed when pronouncing it.
  In the middle of a word, it's a voiced "k" just like in English.
"n" = Very similar to the "n" in English.
"d" = This is another sound some find difficult.  At the beginning of a word or
  phrase, this is actually a "t" sound, without the aspiration (that "h" puff of
  air that comes out when an English speaker says a "t").  The muscles of the
  throat, tongue, and palet should remain fairly relaxed when pronouncing it.
  In the middle of a word, this should be a voiced "t" just like in English.
"r" = This sound never really sounds too much like an "r" from English.  In the
  middle of words, between vowels, this sound isn't too unlike the Japanese
  "r;" a flap of the tongue against the roof of the mouth near that ridge
  behind the front teeth.
"l" = Although written with the same jamo (character) as "r," this is the sound
  that comes at the end of a word or a syllable before a consonant.  Sometimes,
  it sounds to an English speaker more like an "l," and sometimes, it sounds
  more like an "r."  The tongue typically doesn't touch the roof of the mouth,
  and slips farther back some than the "r" sound.  It's close to where the
  "y" sound comes from, which is why it's sometimes even written as "l(y)."
"m" = Very similar to the "m" in English.
"b" = This is another difficult sound for some.  At the beginning of a word or
  phrase, it's actually a "p" without the aspiration (that "h" puff of air that
  comes out when an English speaker says a "p").  The muscles of the throat,
  tongue, and palet should remain fairly relaxed when pronouncing it.
  In the middle of a word, this should be a voiced "p" like in English.
"s" = A "soft" "s" sound, this sometimes sounds like a "z" to some people, and
  sometimes comes with a soft aspiration (that "h" puff of sound that comes out
  when English speakers say a "p" sound).  In other words, don't "hiss" out the
  "s."
"sh" = This only occurs before the "i" and "y" sounds.  It's technically the
  same "sh" that occurs in Japanese (or, at least, very similar); it's actually
  on the pallet.  I won't get into too much detail about that here.
"ng" = Though many English speakers think of this as two sounds or a cluster,
  it is, in fact, one sound.  It's the same as the "ng" in "rang" or "doing."
"j" = This is another difficult sound for some.  At the beginning of a word or
  phrase, this is actually a "ch" sound minus the aspiration (that puff of air
  that comes out when an English speaker says "ch").  In the middle of a word,
  it's a voiced "ch" like in English.  The muscles of the throat and palet and
  tongue should remain fairly relaxed when pronouncing it.
"ch" = Though the muscles of the tongue and palet and throat should remain
  relaxed, a puff of air should follow this the same as it does in English.
"k" = Before a vowel, this sound should be a "k" followed by that puff of air
  found in English, but the muscles of the throat, palet, and tongue should be
  fairly relaxed.  At the end of a word or before a consonant, this is a
  "stopped" sound.  In other words, a "k" is said, but air is not released,
  like the second "c" in "cactus."
"t" = Before a vowel, this sound should be a "t" followed by that puff of air
  found in English, but the muscles of the throat, palet, and tongue should be
  fairly relaxed.  At the end of a word or before a consonant, this is a
  "stopped" sound.  In other words, a "t" is said, but air is not released,
  like the "t" in "patsy."
"p" = Before a vowel, this sound should be a "p" followed by that puff of air
  found in English, but the muscles of the throat, palet, and tongue should be
  fairly relaxed.  At the end of a word or before a consonant, this is a
  "stopped" sound.  In other words, a "p" is said, but air is not released,
  like the "p" in "knapsack."
"h" = Very similar to the "h" in Japanese, this is a "hard" "h" sound, found
  usually in the back of the throat.  Before an "i" sound, the "meat" of the
  tongue pushes up towards the front and top of the palet with the tip of the
  tongue lowering somewhat, and before the "o" or "u" sounds, the lips purse
  to give a whistled puff of air almost like an "f" sound.

Here are your typical vowels:

"a" = Almost like "aw" or the "ough" in "ought," this is your typical "ah"
  sound most other languages have for "a."
"oe" = This sound is difficult for non-native speakers.  Usually, you can get
  by with saying an "uh" like in "uh-oh."  It's actually said with a more open
  mouth and noted with a schwa oftentimes, and sometimes will sound almost like
  an "o" to English speakers.
"o" = "oh" as in "Oh!"  Actually, the lips are quite pursed to say this, almost
  like an "o" with an umlaut, if you know German.  Some speakers almost bring
  the lips completely closed and up against their teeth at times.
"u" = "oo" like "Ooh!"  Actually, the lips are quite pursed to say this, almost
  like an "u" with an unmplaut, if you know German.  Some speakers almost bring
  the lips completely closed and up against their teeth at times.
"eu" = This is another difficult sound for non-native speakers.  The tongue is
  placed forward in the mouth, almost near the front teeth, and the lips are
  held spread open.  Sometimes, people say you should do that "ewww" thing that
  Lucille Ball did in "I Love Lucy" to make this sound.  Some others suggest
  that it's close to the "i" in "it."
"i" = "ee" like in "Eek!"
"ae" = This is yet another hard vowel for most non-native speakers.  The tongue
  usually lies quite flat and rests near the bottom front of the mouth, and
  the sound that results is sometimes like the "e" in "pet" and sometimes a
  a little more like the "a" in "pat."  Actually, many Koreans can't hear the
  difference between these two sounds in English too well.
"e" = Like the "ay" in "pay," but perhaps a little more back in the mouth.

Here are the diphthongs:

"ya" = "y" + "a."
"yeo" = "y" + "eo."
"yo" = "y" + "o."
"yu" = "y" + "u."
"yae" = This is almost never used.  "y" + "ae."  Usually, when this character
  is written, a "ye" is read.
"ye" = "y" + "e."
"wa" = "w" + "a" (actually, "o" + "a", but we're splitting hairs)
"wae" = "w" + "ae" (actually, "o" + "ae")  Some native speakers pronounce this
  the same as "ae."
"weo" = "w" + "eo." (actually, "u" + "eo")
"we" = "w" + "e."  (actually, "u" + "e")
"wi" = "w" + "i"
"eui" = "eu" + "i."  This is written, but pronounced as "e" when it's used as
  a "particle" word that marks possessives or can be translated as "of."

There's another diphthong I'm leaving out that is "o" + "i" but pronounced
the same as "wae" by most speakers.  An older reading that is falling out of
practice is the same as "oe" in "Goethe."

Now, there's something about this language that makes English speakers a little
confused at times--the doubling of consonants.  You may have already noticed
that I said for most consonants that you want to relax the muscles in your
mouth to say it and leave your throat open.  This can actually produce the
so-called "raspy" or "throaty" voice Korean seems to have.
  But, there are also instances in which the first jamo of a syllable is
doubled, making the syllable "stressed."  Although it does convey the same
idea as stressing a syllable in traditional English grammar, a doubled
consonant is pronounced much more firmly with the muscles of the mouth and the
vowel of said syllable is usually said with a bit more closed of a throat.
  There are a few ways to say this for people who want to practice.  Usually,
they say to make the sound after an "s;" "gg" is a the "k" in "skirt," for
instance.  Another is to pretend like someone asked if the sound was different
and you were clarifying ("Did you say 'moe?'  --"No, I said *doe!*")
  These are not voiced sounds, and they lack aspiration.  They're just...said
more firmly.  Here is a list of the sounds that occur in modern Korean:

gg
dd
bb
ss
jj

These doubled sounds and their syllables actually occur after a "stop" sound in
the middle of a word (not after a vowel or "nasal" sounds "m," "n," or "ng.")
In other words, "haksaeng" is actually pronounced "hakssaeng," but I won't
make that distinction, so you should remember it!
  Also, note that "ssi" is pronounced "si" by most Koreans; it doesn't become
"sh" like the "unstressed" version.  Having said that, I should note that there
are some Koreans who do pronounce it as a hard "sh" sound in that instance.
  There are actually more rules about how to pronounce certain sounds before
certain other sounds, such as "k" becoming "ng" before a nasal sound, but I'll
leave that out for now because it deals mostly with the actual han'geul itself.
It's useful to know what sounds can come where in a word, so it might do to
look up how to pronounce written Korean someday if you're interested.
  One final thing I should note is that I will write an apostrophe (') between
the "n" and a "g," if one should follow, to prevent confusion with the "ng"
sound.  I'll write one after the "ng" sound, should a vowel follow it.
  For example:  "han'geul" = "han" + "geul," not "hang" + "eul."
  "jung'ang" = "jung" + "ang," not "jun" + "gang.