The article in About.com lays out the problem: “Small business owners casually name their product or service and step right into the trademark infringement landmine. Has your small business taken the necessary steps to protect against trademark infringement”? Marty Schwimmer, owner-operator of the Trademark Blog, is quoted and provides some good advice, although he makes it clear in this post that he doesn’t like the term “infringement proof” that is used in the article’s title.
P.S. If you want a better practice, check out this Ultimate Guide.