A steady dose of quality companies will keep your portfolio growing big and strong.Dividend investing, like most things in life, can be rewarding if done correctly or a headache if you make crucial mistakes. The key to dividend investing is to pick the right types of dividend stocks. But what does a good dividend stock look like?It will be hard to go wrong if you invest in companies with these three traits:Operating in large industries with room for growth.Consistently profitable, with strong balance sheets ...