Nora Roberts has done it: her 200th book is out in stores!

The Witness is about a secretive, security systems expert with a mysterious past and the man who wants to learn more about her. Readers congratulated the author on her major accomplishment on a Facebook fan page.

Keep those great story lines coming please, one woman wrote.

Roberts is known for her ability to cook up stories -- ranging from the lighthearted to the suspenseful to the dramatic -- that feature strong heroines and men who appreciate them.

Weak, passive people don't make good characters, she told the Washington Post.

She began her first published novel, Irish Thoroughbred, during a snowstorm. The book was published in 1981. Since then, Roberts has published several standalone novels, as well as many a series and trilogy. Roberts also publishes suspenseful stories under the pen name J.D. Robb.

Like other prolific writers such as Stephen King, Roberts is known for her discipline. She partially credits her productivity to the nuns she came across during her Catholic school years.

Discipline, guilt and guilt are really, really excellent tools for the writer's toolbox and the nuns really know how to ingrain that in you early, Roberts said at a 2009 event at the Washington Post.

Words from the wise.

What's your favorite Nora Roberts book?