though I am not an expert with corn snakes, they are easy to care for and don't take alot of time. A 29 gal tank is more than enough for an adult. Paper towel, newspaper, or aspen shavings are good for substrate. The lid needs to be tight and secure. I used a wooden frame with aluminum screen stapled to it. It fit snug enough that the snake can't push it out...or at least he never did anyway. It's tight enough I sometimes have a hard time getting it on.
I used a human heatting pad set on low as the undertank heater. For glass aquariums, you have to prop up one end where the pad goes, as you can't put weight on these heating pads. Just make sure the heating pad still has contact with the bottom of the tank. For light, I used a 60W household bulb on a timer so it was only on about 14 hours a day. During the summer, I didn't use the light as I found it was getting too hot in the tank during the day.
You need two hides, one in the warm side, the other in the cool side. Also a large water dish (big enough for the snake to soak in) that is secure enough to tip over (a dog water dish works great).
For baby snakes you feed once every 5-7 days, feeding mice no bigger than 1.5 times the girth of the snake. (mouse girth to snake girth that is). As the snakes get older, feeding them once a week is fine. Once the snake is near adult size you can switch to rat pinks to fuzzies, if your snake is eating adult mice without any noticeable bulge.
You can feed in the same tank if you don't use any loose substrates. Otherwise you can just cover the substrate when you feed, or put it in another cage.
Corn snakes get about 4-5 feet in length, come in a variety of color and patterns, are very docile and easily handled. Young corns may be a bit nippy or skittish but calm down with gentle slow handling.