A job candidate recently applied for a clerk's position at a newspaper. In addition to her letter of application she was asked to fill out a standard employment application. The form provided room for her to write the other skills she possessed that she would bring to the job. Her answer was, "I proofread good." Well, well. Suffice it to say, she wasn't seriously considered for this or any other job that had anything to do with written words!

This job seeker's mistake is not uncommon according to Joyce Lane Kennedy, author of "Cover Letters for Dummies." In her book, Kennedy says that three out of four cover letters contain typos or grammatical errors that remove the applicant from the pool of candidates. Think about it. Would you want to hire someone who failed the equivalent of an open-book test?

In today's world of communication via e-mail, instant messaging and text messaging, the ability to string sentences together in an understandable fashion is crucial. Whether you work in the mailroom or the boardroom, people need to understand what you are saying. Documents littered with typos are an embarrassment to the author and to those who must read them. David Boeckmann, former executive for Procter and Gamble and founder of Stellar Interviewing Concepts, tells how many potential candidates weeded themselves out of serious consideration at P&G by sending letters of application to "Proctor" (instead of Procter) and Gamble. Don't lose an opportunity to interview for a job you really want. Protect yourself by learning to proofread.

Here are some proofreading Do's and Don'ts recommended by communication experts:

DO minimize interruptions by turning off your phone, turning away from your computer, and closing your door. Breaking your train of thought could result in missing words, poor edits or missed typos. Some successful communicators minimize interruptions by leaving their offices or cubicles in order to proofread their work.

DON'T proofread alone. Always ask someone you respect to proofread your document after you've reviewed it. As the author of the document, you may not see obvious mistakes that others will spot right away.

DO focus on one word at a time. Go slow. Make sure each word is spelled correctly. If you're unsure, look it up.

DON'T think about what the words mean. If you think about meaning, you'll see what you expect to see, not what is actually there. This is especially true when reviewing your own writing.

DO break big pieces of text into smaller chunks to avoid slipping into automatic reading mode.

DON'T try to find every mistake in one pass. Consider letting your eyes rest between proofreading passes. Look for different problems each time you read the document.

DO check for easily confused words, such as "no" for "not," "you" for "your," "if and of," "a and an." Pay special attention to contractions like they're, we're, it's and that's. They are easy to confuse and won't be caught by spell check.

DON'T overlook homonyms. These are words that are pronounced the same, but have different spellings and meanings. Even professional writers have been known to overlook homonyms. Make sure you've used the correct "there" or "their" and "too" or "to."

DO read the document backwards. Reading backwards encourages you to look at each individual word outside the context of a sentence. You are less likely to miss spelling errors this way.

DON'T rush yourself. If possible, take a break between writing and proofreading. One of the most popular proofreading techniques is to let the document sit overnight. This approach is highly effective for people who are most alert for spotting errors in the morning.

DO proofread aloud. This will slow you down and help you catch more errors. Silly mistakes like "broad member" instead of "board member" can be costly. One applicant referenced her previous job as head of "pubic relations" instead of "public relations."

DON'T just read from the screen. Always print out each document you create. Not only does this give you a different perspective, it will also help you see any formatting or pagination problems.

DO look for consistent formatting. Check that all headings are treated the same - bold, underlined, etc. And, check the capitalization and punctuation consistency in bullet points.

The ability to catch mistakes and typos is a skill everyone needs. So the next time you write about your experience as a bored member - err, board member - make sure you proofread your text carefully. Your career might depend on it.