All you need to do is just print the extract out and read it to your class. See if they can work out what genre it is. This is a useful way to start or end your lesson.
Why not come back regularly and collect the extracts?
 

This extract was taken from The Introductory Encyclopaedia of British Wild Animals Volume 3 by Michaela Morgan and Colin S. Milkins

Mole
Scientific name: Talpa europaea

Moles live under the ground in dark tunnels. Their strong front legs, claws and flat paws make them very good at digging. They do not need good eyesight. They use their sense of smell to find their way around.

Home: Grassland, woodland, gardens.

Young: 3 to 4 babies born underground.

Food: Worms, insects.

The encyclopaedia used for this extract is part of The Longman Book Project series. Click here for more information.
Why do we use encyclopaedias? Perhaps you can discuss alphabetical order with the class? Why not ask them to find something out about other animals in an encyclopaedia? Why do moles 'not need good eyesight'? What are moles very good at doing? Has anyone in the class seen a mole before?