One book suggests planting 4 corn seeds in a hole, then after the corn has grown a couple of weeks, plant a few bean seeds around the corn. He doesn't say how big of a hole, or how close together these corn seeds should be. The soil blocker material had suggested that it is ok to plant 4 corn seeds together in one soil block (and plant them that way), so we are combining these methods by planting the soil blocks already growing, and bean seeds around. Two (4 per block) we planted in holes about 10" in diameter with 4 bean seeds planted around the corn. One hole we left a couple of inches to be filled in later, as the corn & beans grow. The other hole we filled in now. I had started two more soil blocks with 2 corn seeds each, so we put these two soil blocks together in another hole with the bean seeds around.
Another book suggests a hole about a foot in diameter, with 4 corn seeds planted about 8" apart. This hole should be filled in later. We did two holes this way, and will plant the bean seeds after the corn is a couple of inches tall.
Another book suggest planting 6 corn seeds in a circle, 24" diameter, with each seed 12" apart, one in the middle. The book also suggests planting corn seeds in a trench (when planting in rows), to be filled in as the corn grows, to give it extra support, particularly in windy areas. I combined these two methods to make a circular trench to plant the 6 corn seeds, and a hole in the middle. It looks like a donut. Later, we'll plant the bean seeds somewhere around the corn.
All methods mention planting winter squash around the corn, to shield the soil from the sun to keep the moisture in, and also to keep animals out of the corn & beans. I had started 4 butternut and 4 acorn squash in blocks. This is too many for the area, but I planted them all anyway, in case some don't make it. I can always kill a couple later if I have to.
The fourth sister is bee plant (Rocky Mountain Bee Plant, as planted by the Anasazi indians) or bee balm. I started plenty of bee balm and planted four of those around the corn. I have some seeds planted in blocks for the RM Bee Plant, but they haven't sprouted yet.