Mahou Shoujo means Magical Girl! Today, I'm gonna babble about it cause it's an addiction, hehe...
(Taken from http://en.wikipedia.org/wiki/Mahou_shoujo)
Magical girls belong to a sub-genre of Japanese shōjo anime and manga. Magical girl stories feature young girls with superhuman abilities who are forced to fight evil and protect the Earth. They generally possess a secret identity, although it can just refer to young girls who follow a plotline involving magic and a transformation (such as Full Moon wo Sagashite). Magical girls are known in Japan as majokko (lit. "witch girl"), though this term is generally not used to refer to modern magical girl anime. Sally, the Witch in 1966 is seen as the first magical girl anime.
Magical boys are much rarer, but easily identifiable as they are designed along similar lines such as with D.N.Angel. A magical girl should not be confused with a catgirl or a magical girlfriend. Sometimes, the catgirl and magical girl character types cross over; the magical girl may have cat ears and tail as part of her costume or a catgirl could have some form of magical powers. Examples of these include Tokyo Mew Mew and Hyper Police. A magical girl and a magical girlfriend typically differ in that the magical girlfriend is not the protagonist.
Such animes I will recommend you to watch is: -
1) Sailor Moon
2) Card Captor Sakura
4) Mahou Shoujo Lyrical Nanoha [All Series]
5) Yes! Precure 5 [Highly recommended!]
6) Tokyo Mew Mew7) Sugar Sugar Rune
8) Pretty Cure
9) Mermaid Melody Pichi Pichi Pitch
10) Ojomajo DoReMi
13) Puchi Puri Yuushi [Petite Princess Yucie]
Sore dake desu~ Hai! Dismissed XD
PS: Don't mind if it's messed up.... Un~