Our guest today is Heather Flett, mom of two and co-founder of rookiemoms.com, a blog for first-time parents. (Check out the spin-off book,  The Rookie Mom's Handbook.) She also writes about local activities for preschoolers on "Being Savvy Berkeley & Oakland," a blog found on The SavvySource. Here are five of her favorite free things to do with kids in San Francisco's East Bay:

Little Farm in Tilden Park: Admission is free for all ages, although the animals will pay more attention to you if you spring for some lettuce or celery. Tilden's Little Farm has cows, pigs, goats, chickens, and more. If you keep walking down the wide path, you'll also discover a little gem of a pond that toddlers can "hike" before or after sharing a snack.

Berkeley Marina: Where you fly kites or just run around, the goal of the day is to wear your kids out for a nap or a good night. Drive into the marina from University Street, and follow all the roads to the right.  There are paths to run, squirrels to chase, and kites to be flown. (If you don't bring your own, there will be many others out to watch.) On one visit, we saw a fun dad launching rockets and he let Holden chase down the shrapnel. You might be so lucky!

Temescal Farmer's Market: This open-air market in nearby North Oakland is open on Sundays from 9am to 1pm, year-round. Park on Hardy Street, a dead end street off Miles Street in Rockridge. First stop: FROG Park at the head of the "greenbelt," where you can let the kids play for a while. Then, following the creekside path, it's a three-minute walk to the Farmer's Market. Ask anyone meandering on the path for directions.  Let your kids dawdle along the creek if they're old enough, or keep them focused on finding the frog illustrations imprinted in the cement if they're too young for creek play.

BAM: Not only is the Berkeley Art Museum, or BAM, a fun place to hang out in the vibrant student district of Berkeley, but admission is free on the first Thursday of each month. It's a great place for peoplewatching, even if you never make it into the museum itself. Before you visit, see my tips on entertaining a preschooler at BAM.

Edible Schoolyard: Located at Martin Luther King, Jr. Middle School, the fabulous Edible Schoolyard was founded by famous foodie and activist Alice Waters. The one-acre community garden is a classroom enrichment project that gives urban public school kids hands-on experience in both the garden and the kitchen, instilling a greater understanding of the seed-to-table connection. Thus, the trick is to go during non-school hours (after school, weekends, summer break are all fine), and then just enjoy the experience of seeing plants and chasing chickens.