The first time you get in a car with your kid at the wheel is probably the first time he's ever been at the wheel of anything, unless you're the kind of family who lets the kids drive an old beat-up pickup truck all over the farm. You guys probably don't need 10 tips for driving lessons, though. You've got fences to mend and cows to birth. Get back out there!
For the rest of us, it's worth remembering that the placement of the pedals and switches and knobs and everything else is brand-new for your kid. There's no reason for the gas to be on the right and the brake on the left; that's just how it is, and you simply have to get used to it. The only way to get used to it is to take a deep breath, put those hands on the wheel at 9 o'clock and 3 o'clock (that's right -- it's not 2 and 10 anymore, Gramps) and practice.