Adwords work, but they can be expensive.
You bid against your competition, anywhere from a dollar to thirty or forty dollars for one click. So when setting up a campaign, be sure to start out with a small budget, and low "Cost per click" value
If you don't specify a region in you Country, province, or city, you may be paying for adwords, in regions that you don't provide your product or service.
Limit the time of day that the Adwords are active. If you product is a business product, sell it during business hours only.
The first position is the most expensive one, be happy with third or fourth. You will spend half the money there.
Tell Adwords how quickly or often you want to ad to be shown, given your budget.
There are no magic formulas, so experiment, it is fun.
There are lots of books and articles on how to navigate and set up Google adwords.