For each bed you will need:
Three fence pickets. You want 1x6 square top pickets, 6 ft long. Don't mess with any nasty treated wood or try to do with plain pine or hemlock boards. You want red cedar, and the ones with the darker red and brown colors are the most rot-resistant. They should cost anywhere from $1.25 to $2.75 each, depending on the grade and where you get them.
Two 1 ft stakes, so get a couple of feet of cedar 1x2 material for each bed you plan to make.
Eight #8 x 2" and two #8 x 1-1/2" screws, flat head if you have a countersink, otherwise pan-head. Get them in stainless if you like, but any decent galvanized or 'gold' coated will be fine.
Cut one of the boards into two equal lengths, about 3 ft. These are the ends. The uncut long boards are the sides. Important: Cedar tends to split, so predrill and countersink the sides, about 1" in from each end. Screw the sides to the ends.
|Put the screws an inch or so in from the end of the board to reduce splitting|
|Reinforcing stake at the middle of each long side|
Now fill the bed with a nice mixture of compost and soil, and stir in any bone meal, lime, or other amendments you might need, and get gardening.
|Two of my beds. Herbs in the back, berries in the front (and a garlic escapee)|