It's not every successful author who does a world book launch in a small community school, but that is part of what makes Pallaskenry's Darren O'Shaughnessy so down to earth. The talented writer, in his late 20s, launched Vampire Mountain, book four in The Saga Of Darren Shan, in Gaelscoil O'Doghair, Newcastlewest, much to the delight of the awestruck children. He had already been at the school to promote his third book in the vampire series, Tunnels Of Blood, last year. "I was there last November and I really enjoyed it, so I decided to go back there to do the launch," he said.

No stranger to success and all the attention it brings with it, Darren has now been writing full-time for the past five years and was 26 when he had his first book published. "I went for an agent, but it was difficult to get an adult book published even with an agent," he says. Ten books have now been written as part of his series of children's books, of which he hopes there will be 20 in total. Not only has he signed a lucrative $1million deal with Warner Brothers for the movie rights to his children's books, Cirque Du Freak and The Vampire's Assistant, but the first in that series, Cirque Du Freak, released in the US in April, has just entered the top 10 bestsellers in America. This is something Darren describes as "very exciting".

For a man who is influenced by Stephen King, and describes his first adult book as "a cross between The Exorcist and The Godfather," Darren is extremely affable, down to earth and proud of his Limerick roots. His dad works for a plant hire firm and his mother teaches in Askeaton National School. And what do they think of their son's success? "They love it; they think it's really great," he grins.

Darren was always interested in writing, and his talent was nurtured by mum Breda, a teacher in Askeaton National School, where he was a pupil. He attended the local Salesian College before studying sociology and English in London, and then worked for a time in Irish Multichannel. But he had always known he would be a writer. "When I was a teenager, I decided writing was what I really wanted to do as a career," he says. "I started off with adult books, and the children's books started as a sideline originally."

His first book, Ayuamarca, was described by critics as "reminiscent of the best of Clive Barker and Iain Banks." Set in a nameless city built by the Incas, Ayuamarca tells the tale of a young man who wants to be a gangster, and follows his adventures. That was followed by Hell's Horizon, a detective story with a slight fantasy twist, which hit the bookshelves in February 2000. Cirque Du Freak was Darren's first teen horror book. Writing under the name of Darren Shan, the story centres around two boys called Darren and Steve, who get tickets to an illegal freak show full of magical performers.

So was it difficult to shift from adult fantasy/science-fiction books to writing for teenagers? "It took a while to get used to writing children's books," he explains. "My books aren't like Postman Pat or Goosebumps! They're written in a dark style, with adult themes, but also written in a way that children can access. It's quite difficult to write for children because you have to find the right tone of voice. Lots of people talk down to kids, so it can be quite tricky to find a middle ground."

He continues to write 10 or 12 pages every day on both his children/teen novels, and a fantasy series for adults. "I still manage to write a lot and travel around. I've been travelling around England and Ireland with my books a lot." A fan of novelists Stephen King and Clive Barker, his writing is in the tradition of Oscar Wilde, Jonathan Swift and Bram Stoker. And when he hasn't got his head glued to his computer screen or stuck in a book, Darren loves to watch a good film. Videos and DVDs line the walls of his house, including everything from silent films to horror and romance. There can never be enough material for his vivid imagination to feed on. "I've got loads of ideas bubbling around in my head, and every now and then I pluck a few out and use them," he laughs.