Calculate the number of stones you'll need for the edging by measuring the perimeter of the bed (in inches) and dividing it by the width of the stones.
Lay the stones on the ground with the back edge of the stones where the lawn and bed meet. Make a score line in the ground with an edging shovel an inch away from the stones along both the front and back edges. Do this around the entire bed and remove the stones.
Dig a trench between the two score lines, digging deep enough to contain half the stone. Flatten the bottom and sides of the trench and tamp down the soil on the bottom to compact it.
Place a stone in the trench on the end. Check the stone for level and tap it down with a rubber mallet if needed.
Lay the second stone in the trench next to the first one. Lay a level across both stones to make sure they're even. If necessary, tap on the second stone with the rubber mallet.
Continue laying stones in the straight portions of the trench using this technique.
Place stones into the curved areas of the trench. You can either purchase curved stones or cut standard stones to fit.
Back-fill the gaps around the stones with dirt.
Water the soil around the stones to get it damp and gently tamp the soil until it is flat and compacted. This will help keep the stones aligned.