Check one of the many on-line home school support group directories. You can search by geographical area until you find your hometown.
Locate your state or province home school association and contact them to find other homeschooling families in your area. They may already have a support group, or be interested in starting one.
Pound the pavement. Not literally, of course, but if you've exhausted most of the available on-line resources, you might want to start checking locally. Believe it or not there are still some home school support groups that don't have a web presence. Visit your local library, educational book store, or community center for more information.
Check Yahoo Groups. If you don't have time to devote regularly to attending the events of a local homeschool support group, you might enjoy being part of an online homeschool support forum. Imagine waking up to an email that says "Meet us at the park at 10am," you could be doing P.E. in the park before lunch.
Check message boards. The State homeschool association has a message forum, as do most popular homeschool support magazines and websites. Members can post questions to the group on the message boards for anyone to offer answers or personal experiences. Message boards are the next best thing to chatting over the back yard fence.
Check the publisher's page for your favorite homeschool philosophy. The Well Trained Mind, for example, has a forum called the, "Beehive". "Charlotte Mason" users also have several forums as well.