Joe,
Tim has some very good advice, I have a few friends that use no incubator at all. In Florida, corns hatch in the wild with little trouble. I prefer a more controlled temp. One or two clutches may be incubated in your house inside a Hova-bator. These units are inexspensive(40.00 dollars) and reliable. One problem I have had with them is they tend to let moisture escape easily. So monitoring humidity is a 2 day event. I found that a piece of damp paper towel over the egg bin, will help retain moisture. I use spaghnum moss if the eggs are stuck together after laying. The moss holds moisture well and the tanic acid in the moss helps prevent the growth of bacteria on the eggs. If you find the eggs soon after laying, you may be able to seperate them. If that is the case, course vermiculite is excellent as a media. I personally don't care for perelite, but I know many people use it with great success.
I hope this helps!
Best of Luck!
Matt L.