Stories
A number of my favorite and most popular short stories have been archived at Fictionwise.com and are available for download.  And several of my out of print books are available as eBooks.  To check them out, go to:

Kindle

Kindle UK

Smashwords

Barnes & Noble

Kobo

iTunes

Diesel

Articles on the Craft of Writing
OA number of my articles that I wrote for Writer's Digest can be downloaded.

Writing Killer Suspense

Plotting and Outlining

Managing Multiple Points of View

The Long and Short of Writing Short Stories