Virgina Woolf would seem to have little in common with present-day teenagers blogging online, but the literary novelist started Susie Day on a trail which led to young people's cyber-life on the Internet.

Susie, author of the award-winning Whump!, has just published her second novel, Big Woo!, to acclaim from the teenage fiction market.

She said: "I got into blogging and social networking when I was doing research for a doctoral thesis on popular representations of Virginia Woolf.

"It was the early days of social networking, all on forums and message boards, but I was really intrigued by the close relationships these online friends seemed to form.

"The technology's moved on, but the same issues come up, about privacy, intimacy, creating a virtual persona. Alas, the thesis is still in my airing cupboard, not quite finished."

At the ripe old age of 33, she claims that her job working with students at St Clare's International School in North Oxford really keeps her on her toes and up to date with what goes on in teenagers' lives.

Susie, originally from Penarth in South Wales, said: "I moved to Oxford when I came to college here at 18 and never went home.

"It's a lovely place to live because you have a weird and wonderful mix of tourists and students. I used to work as a tour guide at the Bodleian Library, but found it hard to concentrate on giving visitors important historical information while I was editing the latest chapter of my book in my head the whole time."

"I am a warden at St Clare's and look after groups of girls aged between 15 and 18. They are all boarders, so very independent and grown up, and are very useful material for my books.

"I am lucky to have such a captive audience. I gave them copies of Big Woo! and they loved it. My work really keeps me in touch with the teenage audience that I write for, and I have a lot of teenagers in my family, too, as I am an auntie five times over."

Big Woo! is the story of serafina67, the online identity of Sarah, a bright but troubled 15-year-old with recently divorced parents. Despairing at having been sent to Crazy Pete the Therapist by her worried folks, Sarah tentatively starts to blog her life and experiences online.

The whole book is written like a blog, so we only know what serafina chooses to tell us, and we only get to know her friends from the conversations they have online.

So why write a blog novel? Susie said: "They say write what you know' - and I'm a big Internet geek.

"There's always a lot in the Press about the dangers of the Internet, the nasty stories about kids being groomed in chatrooms and so on, and I wanted to explore blogging and social networking in a more balanced way, to show the positives too, the reasons why so many of us live half our lives online.

"It throws up loads of questions about trying to find your real identity, which is such a huge thing when you're a teenager.

"Plus, I liked the idea of the writing challenge: whether you could actually tell a story, or create distinct characters, without all the descriptions and so on you usually get in a novel."

Susie started writing when she was seven. "I remember being seven years old, and sternly making myself promise that I would write children's books, rather than any other kind - as if being a writer was a given, somehow.

"I don't think I ever seriously considered anything else when I was growing up, to be honest.

"I have also written some awful poetry, multiple unfinished novels, excruciating short stories and terrible TV scripts. All of these are, of course, safely stowed under my bed, or got sent to the recycle bin years ago.

"My first book, Whump!, in which Bill falls 632 miles down a manhole, won the BBC Talent Children's Fiction Prize and came out in 2004. It's very different from serafina's story, though and is a fantasy adventure for 8-12s.

"My next book isn't a blog-novel, but the Internet and how we use it is still a huge part of the plot - and there's another smart-yet-daft heroine at the centre, of course.

"It's about cups of tea, secrets, and imaginary boyfriends. I can't give away the real title, but if you see me talking about Biscuits and Lies on my blog, that's the one."

She added: "I really like to write books for children and teenagers and I think that's what I will always stick to. It isn't easier writing for children - in fact, I find it's quite the opposite, and that younger people are far more discerning than we give them credit for. But I think children's books are the best - they are fun to write."

Despite new technology, she believes children's and teenage literature has never been in better health. "Lots of people seem to have this idea that writers have a sort of apprenticeship writing for children before they become qualified' to write for adults - it's not true at all."

Big Woo! has been well received by its target audience of teenagers (mostly girls) who are keen to grab a book that has a character they can identify with. Susie added: "Big Woo! got lots of positive feedback, and it's always great when people who you are not related to actually think your book is good!"

Big Woo! is published by Scholastic at £6.99.