The Toad Road Chronicles: The Gatekeeper, The Book, and the Portal to Another World by Luther Kross
Apart from the infamous Christmas Eve slaughter of 1999 - the murder/suicide in which his father murdered his mother and then killed himself - Donnie DeWitt is your average teenage kid. That is until the day that his long-dead father appears, dragging him into a world of dark secrets, black magic, and eldritch monstrosities. Soon, Donnie finds himself to be the only thing standing between our world and the would-be evil gods that wish to bend it to their wicked wills. Can he stop them in time?