You don't have to check up on everything, but a little research can't hurt. People sometimes make gross exaggerations, and it could prevent you from hiring the wrong person.

Get the applicant's permission to call previous employers. Then check on the previous jobs, dates, salaries, and skills. Depending on the requirements of the position you are filling it may be a good idea to verify any degrees or licenses the candidate has included in her resume. Specific references given to you by the candidate are also fine to call, but they're obviously always people who will say good things about the person. These types of references should therefore be taken with a grain of salt—call one and that will usually provide you with all the praise you need for this person.

Depending on the particular position for which you are hiring, you may also want to run a criminal background check. Day-care providers need to be sure anyone they're considering does not have a record of sexual assault. You certainly do not want to learn the bookkeeper you are about to hire has a felony record for embezzlement.

If the factual information the applicant provides is incorrect, be suspicious. Make sure, however, that if you call a company to ask about someone who worked there seven years ago, that you're talking to an individual who can look back in the files (assuming the company keeps files that far back). Just because someone working there at that moment never heard of the person, that doesn't mean she didn't work there in the past.

Be consistent and check up on all potential employees in the same manner. This way no one can accuse you of discriminatory practices.