More than 23,000 children from all over Scotland have voted for their favourite books of 2011, from a picture book about a family of vampires to a gritty teen read about choices and risk.

The awards, which have been running since 1999, are open to authors and illustrators resident in Scotland and are split into three age categories. Teachers, librarians and book group leaders sign up their groups in the appropriate age group and then the young judges read, review, discuss and vote for their favourite book. Reviews are posted on the Scottish Book Trust website by the young judges to share their enthusiasm about the shortlisted books.

A debut author, Ross Mackenzie triumphed in the Younger readers category (8-11) with Zac and the Dream Pirates, about a boy with a magical granny who enters dream world and must battle the Dream Pirates who are responsible for nightmares.

In the Bookbug readers category (0-7 years), the winner was Ross Collins's picture book, Dear Vampa, about a vampire family who are baffled by the behaviour of their new neighbours. Thanking all the schools and children who voted, Collins said "I only wish that I could bite each one of them personally."

Nicola Morgan took the Older readers (12-16) prize with Wasted, a boy-meets-girl book about what-ifs. With a charismatic couple, Jack and Jess, at its heart and an unusual forked narrative, based on the notions of luck and chance that Jack lives by, the book is one that has divided reviewers.

"Wasted was a risky book to write, because it's unusual - well, ok, weird - and that meant it was really hard to predict whether readers would respond well. But the risk paid off," said Morgan.

All the winners were awarded their prizes of £3,000 at an awards ceremony in Edinburgh.