This website is a great resource for Brooklyn parents (above). Here are some of their listings for baby classes in Brooklyn.
The owners of Bija opened this playspace a few blocks from their current location and it's a huge hit in the neighborhood. Bija Backyard, located on Tiffany Place in Carroll Garden's West, is a great place to warm up on a cool winter day. This immaculate playspace (no shoes allowed) is decorated in bright colors, which can cure the winter blues. Kids can play with trains, read books or hide in the plastic house that occupied my son Max for hours. For ten bucks, you get three hours of play for your little one. I assure you, they won't be bored, and you won't be disappointed. If you bring a sibling, they're an additional 7 bucks. 

Brooklyn Yoga
474 Smith Street
718- 834-6067

Brooklyn Yoga is a local favorite in Carroll Gardens, and they have recently added prenatal yoga and postnatal/mom and baby yoga to their schedule. In addition they have childcare available for their Thursday classes at 10am and 12pm for only five dollars per child. Prenatal yoga is offered on Wednesdays at 7:30pm and Fridays at noon. Postnatal/Mom & Baby yoga is offered at Wednesdays at noon. 

Every Day Athlete Studio
138 Union Street
718 852 6300

This new studio in Carroll Gardens West offers a number of classes for expectant moms and postpartum moms. Besides a prenatal yoga class, they also offer yoga for labor, post-natal strength, and mommy and me dance. An added plus is that on Monday mornings and afternoons and Saturday mornings, the popular Audra Tsanos teaches her Music for Aardvarks class at the studio. 

Creative Kids NY

Creative Kids NY offers Mommy & Me arts & crafts classes in BrooklynHeights for children ages 18 months - 4 years. The new session starts the week of January 16th, and meets once a week for 10 weeks; each class is 45 minutes long. The classes focus on a variety of creative arts projects, and use materials such as watercolors, tempera and acrylic paint and lots and lots of glue! They try to do all the messy stuff that most urban parents don't want in their apartments - glitter, markers, etc. This class was recommended to me by a local mom who has a two year old. 

The Artistry Project
185 Sackett Street
Brooklyn. NY 11231

This new Carroll Gardens storefront on Sackett Street offers a variety of weekday art classes for ages two and up. Classes run for six sessions (fall session started 11/1) and cost $120. There are weekend classes for ages 3 1/2 and up. They also have a range of birthday parties with various themes for ages 4 and up. So unleash your little one's artistic spirit this winter at this local art studio. 

Brooklyn Bookworms

It's time to register for Brooklyn Bookworms winter session. Bookworms is a 10-week course for preschoolers and their caregivers, which consists of reading books, learning songs, exploring movement, and doing art. All bookworms activities are centered around children's books, poems, and rhymes. This class is featured in the City Baby Brooklyn-- checkout the book for a review of the class. Classes begin Jan 9th. Classes are 45 minutes long, and meet once a week for 10 weeks. They cost $185 a session. Classes are held at Devi, 837 Union street (b/w 6th &7th Ave) in Park Slope on Mondays 9:30 & 10:30 and Tuesdays 9:30 &10:30.