John’s Book Rights Answer
There are two basic answers to this question:
1. Sell the right directly to one of the major mass-market publishers of thrillers. You can easily find out who the publishers are by going to any drug store, grocery store, airport shop, or chain store that sells mass-market paperbacks. Then check out those publishers who sell thrillers like yours.
For their editor’s names, check out the list of first-time novel editors at http://bookmarket.com/first-time-novel-editors.htm. That list is a good place to start.
2. Sell the rights via a literary agent. Sadly, literary agents are as tough to find as thriller editors, often harder. The best place to connect with a good literary agent is at a writer’s conference near where you live (as long as that conference invites a few good agents).
Your second option for locating a good literary agent is to go through the Literary, Subsidiary, & Foreign Rights Agents directory that sells for $6.00 here: http://www.itsolut.com/shop/cgi/shop/cart/add?shopID=12&qty=1&prodID=11038.
But, having gone through that directory recently and approached many agents, I know how hard it can be to find one that way.
Another way is to connect with literary agents via Twitter. You can find a list of 272 literary agents who are active on Twitter here: https://twitter.com/JohnKremer/lists/literary-agents-the-best. Follow their conversations. Interact with them. Retweet them. Favorite their tweets. Then after a few weeks, ask the agents you’ve interacted with whether or not they’d look at your novel for mass-market rights. If they ask for more, be sure to tell them that you are writing more thrillers in the Wallis Jones series.
Finally, and perhaps best of all, ask your writer friends, especially those who have been published. Sometimes they will actually introduce you to their literary agent or editor. And off you go!!!