Zom-B by Darren Shan is the first book in the Zom-B series. Most of the book is narrated from the point of view of the protagonist, B Smith, but at the very beginning there's a description of a zombie outbreak in a village in Ireland.
B Smith is a teenager, and not a very likeable person, being a shaven headed thug at best. This is largely down to the effect of B's dad, who is an even worse person, a racist, wife and child beater. B is not trying to be racist, but going along with Dad - who B loves, despite all his faults - for years has rubbed off, and now B is worried that they are actually becoming racist.
The earlier part of the book introduces B and B's friends. The zombie attack in Ireland has gone viral on the internet, but no-one truly believes it's true, even as more clips turn up. After all, you can do a lot with CGI these days.
Then, B's school is attacked by zombies with a penchant for brains, and B and friends are running for their lives as their classmates are being eaten and turned.
Not the most likeable principal character ever, but that possibly makes B more interesting. A few surprises at the end of the book too.