Like the writing style of the book, the title of The Raven Boys seems straightforward enough. This is indeed a tale about a group of schoolboys from Aglionby Academy who wear raven-crested sweaters and are known by the nickname of "the raven boys." The whole story revolves around how Blue comes to know some of these raven boys personally, and how they develop a friendship and common interest in exploring magical places.
The title comes back into play at the very end, though, when Ronan reveals that he pulled a real live raven from his mind:
"I guess now would be a good time to tell you," he said. "I took Chainsaw out of my dreams." (48.50)
The image of the raven is obviously going to be more important to the boys than just a crest that appears on their uniform sweater. Only time (and the next part in the series) will tell just how significant ravens are.