If you can sing along to Glee songs and dress like Glee cast members, why shouldn't you be able to read a comic about the Glee exploits too?
Well you can! Kinda. The Glee comic book is actually not about Rachel, Finn, and Puck and the other characters - it's about the cast and crew of Glee IRL and not the characters they play. It's part of Bluewater Production's "Fame" series, which gives "a look at the lives of the actors and creative talent" on the show. Hmm... interesting.