I did some research online and found several sites with writing prompts to collect here.
Charlotte Dillon's Writing Prompts: Loads of writing prompts to choose from. And at the bottom of the page, an invitation to join her writing prompt email group, and a link to do so.
: Creative Writing Prompts from CreativeJuices.com Several prompts, organized into categories. You'll need to wade through the adds, but many of these prompts look interesting enough to make that worth your time.
Write Any Genre: Prompts for romance, mystery, sci-fi, fantasy, horror, historical, and fairy tales etc.
Creative Writing Solutions: Story starters, prompts for character development, setting, point of view, and plot development.
It's All About Writing, Nicole Humphrey Cook: Sentences to get you started. The author recommends we keep in mind the who, what, where, and how.
I love coming up with writing prompts. Today, I'm going to give "Who, Where and When" Prompts that you can add the "What, Where, and How" aspects, and tighten up the "Who, Where and When" parts, too. Have fun. Make it as short or as long as you want. The list will go Who; Where; When
A couple >< to divorce; The court house; 30 minutes before their appt. with the judge
High school teacher/Cop; Parking Lot at the football field; Evening time, just before the homecoming game.
Psychic/Psychologist;Career Day Fair; Just after lunch
Veterinarian/Jockey; Horse farm; day before a big race, morning
Professional Party Planner/Profession Party Attendee; Party at a posh hotel; Night, almost midnight.
If you have suggestions for "Who, Where, When" Prompts, add them in the comments.
The greatest rules of dramatic writing are conflict, conflict and conflict. ~James Frey
The story is not in the plot but in the telling. ~Ursula K. LeGuin
If you can't annoy somebody, there's little point in writing. ~Kingsley Amis
In good writing, words become one with things. ~Ralph Waldo Emerson