Don't use Resolve or anything like that that has a stain 'blocker' in it. It has Teflon in it and if the stain doesn't come out the first time, after you use those products even a a professional won't be able to penetrate the teflon. It coats the stain and makes it impossible to remove. I've been told this by several carpet cleaners & salespeople.

Nature's Miracle or a similar product is what I recommend. I prefer Simple Solution. For regular every day dirt, I've been told to purchase steam cleaner solution and mix it with water and use that.