Definitely not. Katy Perry made her mark in the music industry independently and has no connection to any comic book characters. Her success is a result of her talent and hard work in the music world.
I'm not certain who Perry is in 'the good perry bedtime stories' without more information. Perry could be the author of these bedtime stories, or perhaps it's the name of a character that the stories revolve around, like a wise old owl named Perry who tells the other animals in the forest different stories every night.
Della Street is an important character. She is Perry Mason's secretary, and she is very loyal and efficient. She often helps Perry Mason in his investigations and in the office work related to the cases. Another one is Paul Drake, a private detective. He assists Perry Mason by gathering information and following leads. His skills are crucial in many of the cases that Perry Mason takes on.
Another popular one might be 'The Case of the Howling Dog'. The unique premise of the howling dog being related to a murder mystery captured the imagination of many readers. It also showcases Perry Mason's ability to think outside the box when solving cases.