There are several books I use a LOT when I find myself stuck. Three are by writing master Sol Stein: Stein On Writing: A Master Editor of Some of the Most Successful Writers of Our Century Shares His Craft Techniques and Strategies; How to Grow a Novel: The Most Common Mistakes Writers Make and How to Overcome Them; and Sol Stein's Reference Book for Writers: Part 1: Writing, Part 2: Publishing. All three are invaulable treasure troves of great information.
Another one (and trust me on the title) is Telling Lies for Fun & Profit by Lawrence Block and Sue Grafton. Howlingly funny and packed with good info, both of these writers are masters of the suspense/mystery genre, and most of the articles are reprints of Block's work he did years ago for Witers Digest.
Especially for Writers
3 days ago