The instructors are entirely responsible for the classes, monies, and content of their courses. Absolute Write simply provides space for the instructors to describe their course offerings.
That said, these are classes and workshops taught by writing and publishing professionals, classes Absolute Write feels comfortable recommending, taught by people who are known in the publishing industry as agents, editors, and authors. The classes and workshops on writing are by authors who have legitimate publishing credentials; you can find their books in your local library and bookstores.
Barbara Rogan is the author of 8 published novels, and a former literary agent and editor. She offers several workshops for writers, including Revising Fiction, a Novel Workshop and One Good Scene. These are available only to approved applicants and the class size is deliberately kept small.