books to help teens improve their writing skills
 

Can anyone suggest materials (mainly books) for intermediate level teen students to help improve their writing skills in English?
Some of my students will be sitting the PET exam, soon and they're a bit lacking in the writing department. What worries me is the story writing section, as my coursebook hardly provides any examples on that
The class needs to work on paragraph division and sentence structure. They're Italian and tend to write very long and complex sentences, the opposite of what you should do in English.
They should read more, but they are on the go all day and don't have time.
Besides manuals, do you have any tips or activities to share on helping students improve their written English?
Thank you in advance

Re: books to help teens improve their writing skills
 

You might find something useful here: Primary Resources: English: Text Level: General Ficition (Story) Writing

Could you make a checklist together of what features a story needs to have and while/after they write they decide whether they included all the criteria e.g. in your case "Sentences should be short and clear". Maybe you could also include features like "Include at least two time connectives" or whatever seems suitable.

After that you could get them to evaluate two examples of written stories that you've written yourself to ensure they've taken everything on board.

Hope this is a bit helpful!