A family is gathering on Nantucket for a daughter's wedding. Jenna is the bride to be. Margot is her sister and matron of honor. They grew up in Connecticut and summered on Nantucket. Mom died about 7 years before of cancer, and before she died wrote a notebook of guidelines for Jenna's wedding. The Notebook becomes the Bible for the wedding, and Jenna carries it with her wherever she goes and follows it to the letter. While I always got annoyed by mother's who try to control their daughter's weddings, this one works. While some of her advice is outdated, most of it works well.
Jenna's Dad, Doug, is a high profile divorce attorney who against his better judgement married one of his former clients after his wife died. Margot, Jenna's sister, is divorced. Stuart, the groom, is from North Carolina. His Mom is a state senator. The groom's family has marital issues of their own - Jim and Ann split for a while as he had an affair (and had a child with another woman - Helen) and then remarried. There are the stereotypical hookups between bridesmaids and groomsmen.
Despite all of Beth's tips there is a lot of drama before the wedding - nastiness due to step-relationships colliding and cold feet by the bride.
A lot of the side characters are fun as well - Roger the contractor turned wedding planner, Ellie - Margot's hoarding daughter who ends up playing a key part in the pre wedding chaos.
It was a fun read and I will definitely read more of her books. Even though I lived in Massachusetts for 7 years I never once went to Nantucket so don't get most of the island references, but that's ok. One mistake did notice though (as I live in Chicago now) that one of the characters grew up in Cabrini Green (which the author incorrectly says is on the South Side of Chicago). I guess most people think of the south side being the bad part of the city ( which it is) so she assumed that Cabrini is there too when it's really right next to the Gold Coast and at this point is getting gentrified.