Eat food. Mostly vegetables. Not too much.
Diet fads, Lean Cuisine, and calorie counting are all short cut attempts at trying to get around this simple guideline (in my humble opinion at least). If it's bought, paid for, and ready to eat in less than 5 minutes, you may want to rethink it. Shop around the perimeter of the supermarket because The Big, Bad, Bag O' Chips and Mrs. Jiffy Corn Muffin Mix Fo' Yo' Hips are waiting for your hungry behind in those middle isles! And you would be surprised how much eating in the company of friend and family will dictate what and how much you eat (unless your friend is that dude from "Man vs. Food" of course).
That's all for now, but check back for how "healthy eating" is not as much of a mystery as you think. Eat well and be well friends!