Mark Fainaru-Wada and Steve Fainaru, ESPN investigative reporters, discuss their new book, League of Denial: The NFL, Concussions and the Battle for Truth at 7 p.m. Wednesday, Oct. 23 a Copperfield’s Books, 140 Kentucky St. Visit copperfieldsbooks.com for details.

Does your medicine cabinet need a makeover? Mariza Snyder talks on replacing over-the-counter medicines and other drugs with essential oils, part of a whole-foods lifestyle suggested by Robyn Openshaw, aka the Green Smoothie Girl. The class is from noon-2 p.m. Friday, Oct. 25 at the Sunflower Center, 1435 N.McDowell Blvd. Tickets are free and available at eventbrite.com. For questions or details, e-mail seaofbamboo@gmail.com.

Want to be the best childcare person or babysitter you can be? How about a course in Child and Babysitter Safety, offered by Petaluma Community Center instructor Carole Gathman. Included are instructions in child and infant CPR. The class, for students from 11 to 17, is from 9 a.m.-noon Saturday, Oct. 26 at the Community Center, 320 N. McDowell Blvd. Fee is $50-$55. To register, call 778-4380.

Kids are invited to put on their Halloween costumes a little early to enjoy trick or treating at the Bill Soberanes Halloween Festival at the Plaza North and South shopping centers. It’s more accurate to say “treat or treat,” since the Plaza North and South merchants promise “lots of treats – but no tricks.” The annual event is from 11 a.m.-6 p.m. Saturday, Oct. 26 at 259 N. McDowell Blvd. Call 762-2234 or visit theplazanorth.com for details.

Hello, Petaluma! Are you ready for Pumpkins on Pikes? Tara Firma Farms hosts the event, starting at 2 p.m. Saturday, Oct. 26 with food, music and pumpkin carving with all participants having the chance to display their jack o’lanterns on pikes in the corn field. After sunset, the pumpkins are lit. Participants should take special carving tools, a blanket (gets chilly after dark) and, if taking part in the potluck, a plate of food to share. A $10 barbeque dinner is available. Cost is $10-$15. Tara Firms Farms is at 3796 I St. Visit tarafirmafarms.com for details.

Send your Petaluma events listings to Katie Watts at goodegg2004@gmail.com.