You can follow all the goings on in the school by watching the YouTube webisodes which cover plenty of typical issues that teenage babies will face at school. You know, like making friends, dating, passing exams, making the track team or fear squad and stuff like that. There's also books and music about the place.
For example, Clawdeen Wolf is the offspring of the Wolfman (a werewolf). He's werewolf characteristics and behaviors and these often crop up in story lines. Another is Draculaura, who is the daughter of Dracula of work. He cannot be seen in mirrors and cannot go out in the sunlight as you would expect of all self respecting vampires.
The idea of the school with teenage monster babies is the brainchild of toy maker Mattel. And ultimately they sell merchandise, primarily dolls of the main characters and all sorts of accessories. They are fashioned like Bratz dolls but have the unique Monster looks and character traits.
Other characters include Frankie Stein, the daughter of Frankenstein's monster, Lagoona Blue, daughter of the creature from the Black Lagoon and Cleo De Nile who is daughter of the Mummy.
There's other characters that feature in the story lines , like Deuce Gorgon, Ghoulia Yelps, Claude Wolf and Holt Hyde. There's even new characters being added on a regular basis, like the exchange student Abbey Bominable who is the daughter of the Abominable Snowman of work.
The costumes look like nice representations of the outfits worn by the original Monster High doll characters and are officially licensed by the Mattel company. They would make a great Halloween costume for young girls as they have a spooky theme in keeping with the holiday but also look nice.
In terms of costumes, you can only get the main characters currently. Possibly more will be added if the series continues to be popular. The costumes are based on the outfits that the first version of the dolls were wearing. As the characters are wannabe teenage fashionistas they love dressing up in new gear and the latest styles. Hence there's a few versions of the dolls, wearing different gear.