Slug control is actually quite easy. They are rather large, so they can be caught by hand and disposed of. This is another garden pest that be caught by setting out a dish of beer.
While possibly cruel, the most effective way to kill a slug is to sprinkle it with salt. You can trap the slugs by placing a plastic bag in the garden containing two decaying lettuce leaves, 2 cups of bran cereal, and pouring beer over the whole mess. Put the bag out before sundown. In the morning, check to see if the slugs are in there and dispose of them.
Prevent slug infestation by removing dead and decaying leaves. This will remove their primary food source. Coffee grounds and egg shells will also keep slugs away. Just place them around the plants you want to protect at ground level.