Enotes does not have a lesson plan for The Valley of the Dolls, but you may find the quickNotes study guide helpful. It has a summary of the plot, descriptions of the characters, analysis of the themes and social issues, and more. The Related Resources section also has information about movie adaptations, links to literary reviews, and the like.
You might consider printing a copy of the quickNotes for each of your book club members either before or after you've read the book. Talk about what society was like in the 1960s, especially the so-called "high society" of the rich and famous. Does Susann accurately portray the era, or does she exaggerate? Are her characters only stereotypes, or are they fully developed as individuals? Do you agree with the quickNotes descriptions of the characters, or are your perceptions different? In what ways have celebrities changed or remained the same since the 1960s?
I'm sure that after reading Jacqueline Susann's Valley of the Dolls, along with the quickNotes study guide, you'll be able to find many, many topics to discuss.