For information, classes, and more see Oregon Tilth, a non-profit group that advocates sustainable gardening practices and offers a number or organic classes. Their Organic Education Center has free classes every Saturday in West Linn and a resource library. Year round events and workshops occur all over the area and cover composting, fruit trees, container gardening, and beekeeping.
Metro gives free classes all spring on everything from pest control to exotic plants that love our climate: metro-region.org. Also available at their site is a library of documents for green gardening and native plants. Portland Preserve, which teaches canning, also hosts classes in beekeeping and herbal gardening, herbal medicine making, honey wine, and kids gardening classes. The local group Growing Gardens helps create organic, raised bed vegetable gardens and has classes for all levels and ages.