There are two basic types of manga. The first is shounen manga. Shounen feature lots of action and adventure. They have stories that include martial arts and warriors. The second is shoujo manga. Shoujo focuses on romance and drama.
An example of a shounen manga is One Piece by Eiichiro Oda. It's the story of a young man named Monkey D. Luffy who grew up listening to pirate stories. As a result, he decides to set off on an adventure to find the greatest treasure in the world.
Ouran High School Host Club by Bisco Hatori is an example of Shoujo manga. In this story a young girl pretends to be a boy to get into an exclusive, private school. She finds herself in all kinds of trouble as the boys discover her secret.
If you grew up reading comic books and enjoy stories told with pictures, you might want to try reading some manga. Here's a piece of advise though, it reads back to front and right to left. The first time I read one in a traditional manner, and it didn't make much sense.