'Teen Titans: Raven' is a recent graphic novel that's beginner - friendly. It focuses on one of the Teen Titans, Raven. The story is accessible and the art is really beautiful, which can draw in new readers who might be interested in the Teen Titans or just DC comics in general.
For beginners, 'Superman: Up in the Sky' is a great choice. It tells a simple yet engaging story about Superman. The art is easy to follow and the story showcases the core values of the character, like his kindness and strength.
'Batman: The Golden Age Omnibus Vol. 1' can be a good starting point too. It contains some of the earliest Batman stories. It gives a sense of the character's origins and how he has evolved over time. The classic art style is also a big draw.