The book is told through monologues (the narrator changing each chapter), and follows an ensemble of low-life characters. However, its main voice is Renton, a relapsing heroic addict who has wasted his obvious intelligence, thanks to his purgatorial life of addiction, and living off the dole. Renton is perhaps the most decent character in this unremittingly bleak novel, though that's not saying much.
The novel is, however, more than a bleak book full of bad people, and hits poignant notes that shine through the jet-black humour. This makes it a dark delight, and gives you a real idea of how the people amuse themselves in the dull amoral environment of the very real Leith housing estates. This is an excellent novel, which both teaches and entertains.