For the best compost,
you need to ensure you keep turning it over to ensure air
gets throughout, as well as to distribute the heat. Normally,
gardeners do this with a pitchfork by turning over the layers
of the compost - think tossing a salad but on a much larger
scale!
You can aerate
a compost another way. What you need is a perforated PVC pipe
(meaning a piece of white PVC pipe that has holes in it, then
"plant" it in the center of the compost pile. If
your compost is really large, you may want to do a couple
of them.
You can also start
your compost pile with branches at the bottom, which helps
heat rise from the ground without "stopping" at
the bottom layer.