A good diet is important. This doesn't mean you have to diet, it means cutting down on fatty processed foods. It means eating in moderation, and eating a balance of meat, fruit and vegetables, as well as whole grains. It means ready nutrition labels, and staying away from preservatives, and saturated fats. It mean that if you have to have snacks, that they are healthy snacks.
Getting into a regular exercise routine is also important to proper health. Getting exercise doesn't have to mean going to a gym, it means getting out every day, riding a bike, walking around, playing sports with your kids. Even simple things like playing Frisbee, or throwing a ball around gets your heart pumping, and moving around. Take the kids to the park every day, or every other day, it doesn't have to be all day, an hour or so of good cardiovascular activities a day are enough.
Spend more money on groceries that are good for you instead of going out for fast food. Pack a lunch for work instead of grabbing fast food. Not only will it save you money, but save your heart as well. Eat in moderation. Stop smoking, drink less caffeinated beverages, as well as cut down on alcohol consumption. A couple of beers have be proven to have health benefits, but that's all.