I thought it would be good to give you a list of the most basic terms so you can sound intelligent when talking about Manga. I have written it in Romanji which means English type for the Japanese sounding word. Think phonetically!
Manga In Japanese this can mean comic or drawing. It is best known for its innovative panel work and dynamic style of drawing showing full movement and unique angles. Note: Manga consists of 3/4 of the total published material sold in Japan. Three million people a day read Manga in Japan, and are not shy at all to sit next to you on the train and read their favorite Manga. Oddly enough, Italy has the largest importation of Japanese Manga of any other country. The average Japanese Mangaka finishes 12 pages a week, whereas the typical American comic book artist only finishes 8 pages per week.
Mangaka (MANGA-KA) These are artists themselves. Manga unlike most American comics are done entirely by one individual. Massume Shirow (Ghost in the Shell) has been known to use up to 80 drawing tools to finish one page!
ANIME is the Japanese term for Animation. Most Anime is animated in the Manga style of drawing, making it extremely dynamic and fun to watch.
OVA or OAV this stands for Original Video Animation. The term specifically stems from Animation released directly to video without appearing in film or television first, but now has become more generalized to define short series Anime.
Kodomo Manga Kodomo is the Japanese word for Child. Kodomo Manga means children's manga. These comics tend to be simple and comical.
Shonun Manga This manga is targeted specifically towards the male gender. If lots of blood, violence, minor nudity, and just a whole lotta' ass kicking is your thing, then Shonun Manga is for you.
Shojo Manga As you probably guessed, this is manga for the female audience. Angst filled love stories, girly looking pretty boys, and some emotional tension come oozing out of this style manga. Shojo Manga is just as popular ad Shonun manga though, so don't think because it's girly it can't sell.
Doujinshi This is where Japan differs drastically from the American way of things. Doujinshi is fan art done on the professional level and sold. This means that in Japan you could take your favorite comics property do a whole bunch of pin-up art and even stories and sell it legally. Some of these artists are better than the creators themselves, and are top notch when compared to any. Doujinshi has taken off in popularity considerably in Japan in the past 3 years.
Hentai Manga For us perverts out there, Hentai is manga with erotic or pornographic content. Censorship in Japan is very lenient and allows a lot more than any other country. Creamy Angel and Alice First are two examples of hardcore Manga with pornographic content. The art is just as good in these series as any other, but you have to weed through the sea of copy cats and wannabees just like anything else. Sex sells in Japan.
Tachyomi If you hang out in Manga stores regularly you will find that most people don't buy their manga. They just stand in the store and read it until they are finished or have had their fill of it. These consumer renegades are known as Tachyomi, and they have been known on occasion to buy stuff.
Otaku is probably the most over used and misused term. Basically Otaku has been applied to die-hard Manga/Anime fans. The ones who eat, live, and breathe Manga; however, it really is slang for you "freak". In the bluntest terms it means you are a loser and have no life, just like me.
Those are the basic terms to get you going. Here are some more for you who are interested in the world of Manga and Japanese pop-culture.
Minasan (mina-san) If you watch Sailor Moon, you will have heard this. Mina means everyone, san being the polite modifier as in Mr. or Ms. It's often used at the top of the lungs to get everyone's attention or to show support such as "All for one and one for All!"
Kawaii This means Cute! Often it is said wrong, and misinterpreted as Kowai which means scary. Yet Ka-Wa-ii (like Hawaii) is the best compliment you can give to a sexy Japanese girl... in fact I remember this one time that I...um...heh....ah never mind!
Baka This simply means "idiot". You can use it in reference to things stupid, idiotic, dumb, or retarded. It is the most common insult, but remember Japanese are about being polite, so use it as a last resort or with close friends.
Bishonen This is a pretty guy, who often has female characteristics such as a pretty face and long hair. Alan Shazar on Escaflowne is a good example of a pretty boy.
Ecchi (Aye-chi) This is another word for Hentai. Hentai is actually the Korean term for porn, Ecchi being the Japanese term. It literally translates as "naughty".
Fan Service This is more of an Anime term, but can sometimes be applied for Manga. Fan service is the same as T&A shots. Artists will often add bouncing breasts, ass shots, or close ups (typically of the female anatomy) just to have more fun animating. Fans tend to enjoy this a lot, and it has become a common place. Some of my favorite fan service is in Cowboy Bebop in an episode called "Stray Dog Strut". There is a scene where Spike goes to a pet shot, as he is leaving the villain enters and causes a ruckus. All the animals’ escaper from their cages. In the closet sized store, Giraffes, Camels, Horses, tigers, geese, dogs, among with many other animals amazingly escape the local pet store. Fan service doesn't always have to be about boobies.
Fan Sub Because I'm on Animation terms now, Fan Sub is Anime that is subtitled by fans. Often better than studio subs, sometimes not so much. The University of Puget Sound Seattle, WA has one of the most Amazing Anime clubs, and they do great fan subs. Also, Manga will have fan translations often found floating on the Internet.
Chibi Also known as HD (Hyper Deformed) Chibi are those squashed down, chubby kid-like, overly cute Anime looking characters that portray the real deal. Note: Chibi is a derogatory term equivalent to our midget. So only use it when speaking about the drawings.
Mecha or Mech Most of us all know that this is the slang for mechanical in reference to robots. Often mechs are large and in charge, and they like to kick a lot of ass. Note: Gundam Wing.
Japanimation This is a Lazy-Anglo-White-American term for Anime. Most new comers to Anime will use it, and that is excusable, but I can't tolerate veteran Anime watchers using it. Call it a Pika-Pet-Peeve if you will. I don't like the stereo-type of it; I mean Japan isn't the only place that does animation! And america-mation just sounds dumb.
Pika This is a Japanese onomatopoeia. It literally is a "sparkle" or small "flash". Often Pika is used to describe lighting or static electricity. For those of you who know Pokemon, Pikachu is one of the Pokemon and Ash's best friend. Pikachu is a small electrical mouse creature that can only communicate by saying is name in cute and various ways. Just like me.
Pokemon Is the runaway cult hit cartoon series created by Nintendo based of their equally as popular video game franchise! That was a mouth full. Anyway, Pokemon set a new standard in marketing blitzkrieg. Yet you'll find mostly only little kids interested in it, and among them one very pathetic guy. Wonder why I can't get a date? Oh, that's right... my fiance would kill me!
Well, that's about all I can think of for now. Hopefully I helped enlighten the masses about Japanese culture.