2. Rodgers Ranch Urban Farm. If you wanted to come out to Pleasant Hill, this garden at the site of a historic house is wonderful. They have groups working there most Saturdays, and offer informal classes at various times, but it's a real learn-by-doing environment.
If you can wait a while, we will be offering a permaculture "Grow More Food In Harmony With Nature" series early next year, probably starting in February. This is also at Rodgers Ranch, and partnership between Sustainable Contra Costa and the urban farm.