Agatha Christie-- Great ideas for original plot twists for aspiring murder mystery writers. Favourites include Murder on the Orient Express, Crooked House and Cat Amongst the Pigeons. Also easily accessible language that appeals to murder mystery fans of all ages. Clear succinct story line ideas for those writers bogged down in highly complex narratives. 

Marian Keyes-- Really a great writer that appeals to women of all ages. Her plots are both multi-faceted but also easy to follow. See her for good romance novels and easy chick lit ideas.

Wendy Holden-- some simply cracking idioms and similes in these easily-read chick lit novels. Highly original puns. Favourites include Fame Fatale and Marrying Up. A satire on high society. 

Dan Brown-- very good widely known thrillers. See for tips on good and subtle plot twists. Favourite is the less known Digital Fortress. Use of pacy interchanges between characters very good. Fantastic use of the intertwining of fact and fiction to suspend reader's belief and fully immerse them in the story.  

Meg Cabot-- For younger audiences she really has a very good writing style. Simple sentences and use of modern slang words appeal greatly to teenage girls and encourage them to relate.  Furthermore the use of diary style or letters engage younger readers. Great books include Boy Meets Girl, Size 12 is not Fat (series) and the Princess Diaries (series). Also see Jacqueline Wilson books for targeting pre-teen audiences.