Crime fiction includes mysteries, thrillers, suspense, and spy novels. All of these have many subgenres and can easily be their own list or display. Remember that readers who enjoy one often will cross over to read another. If you check out the bibliographic record of some crime fiction titles, you will often see mystery, thriller, and suspense listed as genres.
Again, as with the previous posts, I am going to try to not repeat resources. Keep in mind, many of these resources have information about multiple genres. If you have suggestions, let me know!
Crime Reads is run by Literary Hub and focuses on crime fiction and non-fiction. There are a lot of lists, read likes, interviews, and news about upcoming releases. Beyond fiction, they cover TV, movies, and true crime.
One annoying thing is that those who eschew other genres will promote crime fiction, even those who believe themselves to read only "serious" literature. Setting aside the snobbery and incorrect attitude about the rest of fiction, The Booker Prize, a literary award based in England, does include crime fiction and has some articles and information about nominees.
Sisters in Crime was founded to help promote women in mystery. There is information about chapters, an author search, and a page for librarians. There is also a podcast.
Crime Writers of Color has information about upcoming and recent releases, subgenres, a podcast, YouTube channel, and information about speakers. If you are looking for example, a police procedural to add to a list or display, this is a great place to check.
For information on crime fiction including awards, authors, series, diversity, genres, debuts, and more - visit Stop, You're Killing me.
Mystery Scene Magazine is published four times a year. The website features reviews as well as some of the content from the magazine. Reviews can help you find read alike for your book displays and lists.
The Mystery Writers of America is an organization for mystery and crime writers. Librarians are able to join. There is information about new books by members and more information available to members. The MWA gives out the Edgar Awards every year. There are a number of awards including for non fiction, first novel, and youth titles.
Bouchercon presents the Anthony Awards every year. The convention, run by the World Mystery Convention, has programming for mystery writers. The Anthony Awards are a great way to curate a book display or list of the best of the genre. The nominees and winners going back to 1986 are available on the site.
Hands down, the most popular site I ever talk about in a training is Cozy Mystery List. There is information about books, television, and movies that are cozy. There is a definition of what a cozy mystery is, information about new releases, authors, and a comprehensive guide to series by theme.
Another organization for writers is the International Thriller Writers. They present the Thriller Awards which can be helpful for passive readers advisory. As with other writers groups, librarians can join as associate members.