When a person screens through a large stack of resumes, typically any resume containing an error is discarded without a second thought. Common mistakes, such as; spelling, grammar, and proper formatting are sure-fire ways of ensuring you don't get called for an interview. These types of mistakes display carelessness to a potential employer. At least spelling, grammar, and formatting are easy mistakes to fix. Simply do a spell check and review your resume before you send it off to potential employers.
A major mistake that can prevent you from getting an interview is leaving out important information. Sometimes this can be simple identifying information such as your phone number, or e-mail address. Obviously, you can't get called for an interview if an employer can't reach you. Also, it brings about red flags if you don't identify where you are from. I once felt duped when I contacted a candidate for a phone interview, only to find the person I was talking to lived on the other side of the country. To make matters worse, this candidate wanted our company to pay for moving expenses. Needless to say, he didn't get the job.
Another simple mistake that is surprisingly made quite frequently is using acronyms in a resume or cover letter. When you work for a company, you learn many acronyms; it's almost as if you learn a new language. For example, if I were to apply for a job, I may say that I process criminal record checks, which at my place of work is typically written as CRC in e-mails. No one outside of my workplace would know what I'm talking about if I simply use the acronym, CRC. Also, since employers typically will scan through a resume, even writing "criminal record checks (CRC)" and using "CRC" after that point is a mistake. Potential employers are quickly scanning a resume and may miss a line that defines what an acronym means; therefore, making the rest of the resume unclear. Your best bet is to avoid using acronyms so you can ensure potential employers know exactly what you're talking about.
It's common to make last-minute revisions before sending a resume off to a potential employer. One mistake to avoid is forgetting to save the resume before e-mailing it. You don't want to put a lot of work into perfecting your resume, only to let one silly mistake ruin your chance of getting selected for an interview.
The bottom line is a resume should sell you to a potential employer. You want to project yourself as a quality employee that is capable of producing excellent work. An error-free resume is a great way of ensuring you promote the right message to an employer.