The key stage 3 Literacy across the Curriculum folder (DfEE 2001b) provides a list of types of non-fiction writing and interestingly encourages teachers to provide pupils with an oral example of each type:
Instructions: recipes, giving directions.
Recount: science experiment write-up, match commentary
Explanation: the rain cycle, how erosion occurs.
Information: food in Britain, the properties of mercury
Persuasion: advertisement, manifesto.
Discursive writing: ‘discuss’ essays, magazine article.
Analysis: literary criticism, analytical essay.