Rating: High Four!
Who I'd recommend it to: Fans of the Percy Jackson series, The Girl Who Could Fly, The School for Good and Evil series, and the Half Magic series.
Synopsis (From amazon): When middle schooler Kelly Ferguson’s Halloween plans switch from party-going to babysitting, she thinks the scariest part of her night will be the death of her social life. But then Baby Jacob gets kidnapped by the Boogeyman’s minions and Kelly learns there’s a whole lot more to childcare than free snacks and Netflix. Like chasing shadow monsters, drop-kicking Toadies, and mastering monster-fighting moves like the Naptime Headlock and Playground Punch.
Now, with the help of an ancient handbook and a secret society of butt-kicking babysitters, Kelly sets out to destroy the Boogeyman before he brings Jacob’s nightmares to life. But when the monsters’ trail leads to her school’s big Halloween bash, Kelly will have to prove she can save the world--without totally embarrassing herself in front of her friends.