Simon Vs. the Homo sapiens Agenda by Becky Albertalli. The main character Simon has to be a wing-man to a classmate lest he be outed by him, all while flirting via email with a boy from his class. Another great, and cute, read.
Anything Could Happen by Will Walton. This one is similar to Openly Straight, where the main character Tretch falls for his straight friend, and has to deal with coming to terms with his feelings, and his friend's heterosexuality.
Full-Metal Indigiqueer by Joshua Whitehead
Masculindians : Conversations about Indigenous Manhood by Sam McKegney (Ed.)
Openly Straight by Bill Konigsberg is a really great one. It's about a boy named Rafe who goes to an all-boys boarding school. He wants to experiment by losing the label "gay" and just be known for who he is: Rafe. (A favourite of mine, and an easy, yet insightful read.)