From what I've seen in the Corn Snake world, substrate actually isn't a heavily debated topic. You have the no-brainers... i.e. Sand, pine, and cedar are all bad and total "no-goes." Then you have stuff like the Repti-bark, which, though it works, has a bad habit of disguising poop and carrying mites. And then higher humidity substrates that aren't necessary unless your corn has a serious shedding issue... Then you come to the most highly recommended substrate for corn snakes, shredded Aspen bedding. It's not too dry, not too dusty, corn snakes don't need the damp conditions that might make it mold, it looks nice, it holds shape when the corns burrow (plus allowing them to burrow in the first place), and Aspen doesn't have any of the dangerous chemicals like pine, cedar, and other soft-wood beddings that will cause serious respiratory illness and death.
What you use is up to you. Paper towel works. So does newspaper. Other wood beddings that don't contain pine or cedar. Heck, I've used sterilized organic top soil with some success. Aspen is a common recommendation based on many breeders' and keepers' experiences. In my own experience, aspen seems to be the best for corns.
On a note of heating, yes, heat pads are good. Make sure it covers about 1/3rd of the enclosure, so he has room to escape the heat. Also, make sure you get a thermostat!!! I can't express enough the importance of a good thermostat to control your snake's heating element. I have personally witnessed unregulated heat pads, just plugged directly into the wall, get as high as 140*F. That's plenty high enough to kill your snake.
You can find thermostats for $30 and under if you're on a budget, or find really good ones for $100 or so. With thermostats, you get what you pay for. The cheap ones are... well... Cheap, and you can't know whether they'll fail in 6 months. The expensive ones are generally very high quality and will last a lifetime.
I recommend the Herpstat, in part because I can tell you from my own experience how fantastic they are (compared to the cheap stuff and the Rancos I've used in the past). I've had my Herpstat since I got my first snake 3 years ago. It's still going strong. I've also had several cheap thermostats (namely Zoomed Reptitemp 500R t-stats) that have failed within a year of my having them, and one Ranco that, though it worked and worked well, I was disappointed with the quality and not-so-precise temperature control after being "spoiled" by a good Herpstat. The manufacturer of Herpstat is
http://spyderrobotics.com/. You can buy them (for a few dollars cheaper; Spyder Robotics must not enjoy the tediousness of filling individual orders) from other online stores, i.e. The Bean Farm (
http://beanfarm.com/index.php?cPath=1238_1241). The Bean Farm also sells an Alife thermostat, which is one of the better "cheap" thermostats, if you're on a tight budget.
Also, it might not be a bad idea for you to do some extra reading on corn care if you haven't already.
http://Cornsnakes.com is the BD.org of the corn snake world, and Kathy Love and Don Soderberg (two big, well-renowned corn snake breeders) both have excellent care books.
Good luck!