As a professional resume writer, I’ve seen the same mistakes time and again. A substandard document can prevent you from being called for a job interview, and some mistakes can severely damage your career.

If your resume isn’t perfect, you’re not alone. The following are six mistakes that ruin most resumes and how you can prevent them.

Mistake #1: No Objective or Summary

By not describing what job or field you want to work in, your resume starts off on the wrong foot. You force the employer to read it all the way through to figure out what kind of job you’re suited for. You create more work for a busy reader.

"It’s important to tell the reader what you want to do," says Mike Duthoy, president of Diversified Employment, a recruiting and job-placement firm in Golden Valley, Minn. "After interviewing and hiring 14,000 people over nearly 30 years, I know that employees perform better in jobs they enjoy and are qualified for. Make this clear in your resume’s objective," he says.

If you know the exact job title you’re applying for, include it. Start the resume, for example, as follows:

OBJECTIVE

Marketing Manager whose 10 years of sales, marketing and management experience will add value to operations.

If you don’t know the job title, start your resume:

SUMMARY

Seeking a position where 10 years of sales, marketing and management experience will add value to operations.

Beginning your resume with a clear objective or a focused summary tells readers exactly what you want to do for them. This message establishes rapport, sets the stage for the rest of your resume and will improve your results.

Mistake #2: Focusing on You and Your Needs

This is the worst and most common mistake you can make. Employers don’t want to hire you. They hate hiring. They only hire employees when they have problems to solve. Employers don’t want to spend a lot of time hiring, just as you wouldn’t want to spend more time in a dentist’s chair than you had to.

Your resume must answer quickly the question on every employer’s mind: "What can you do for me?"

Most resumes don’t. Too many start: "Seeking a position where I can utilize my skills in an atmosphere with potential for career advancement…."

"This is a critical error," says Mr. Duthoy. "Avoid coming across as someone who uses employers as a springboard to better jobs."

Employers have their own problems. Most could care less about your career aspirations or desire to make more money.

Consider the following objectives:

"To obtain a long-term career with an organization which has a strong background where I can grow professionally and be rewarded financially."

"A position in sales and marketing where my talents can be utilized to increase market share and company profits while pursuing new opportunities for career challenges with a company who places high priority on customer satisfaction, initiative and quality performance in the realm of product and channel management."

Resumes should tell employers how candidates can add value to their operations or contribute to efficiency as in this summary:

SUMMARY

Seeking a position where 10 years of sales, marketing and management experience will add value to operations.

What hiring manager wouldn’t want to talk to a candidate who’s offered to add value to his operations? You also could say: "will contribute to operations" or "will add to profitability." The wording doesn’t matter. What matters is your focus on helping the employer meet his goals.

Mistake #3: Focusing on Duties and Responsibilities Instead of Results

While what you’ve done at each job is important, what you accomplished and how you made yourself valuable to past employers is even more significant.

Review your daily duties. What were the positive results when you did your job well? How did sales, revenue or efficiency increase? Write down these results and include them in your resume. The more specific, the better.

Instead of: "Responsibilities included implementation of policies and procedures, training of new employees, interfacing with subordinates and vendors and light correspondence."

Try: "Worked with staff and vendors to increase product turnover by 15% and sales by 23% in five months. Also trained 14 new employees, five of whom were rapidly promoted."

Be sure you can prove everything you claim.

"Results are the bottom line," says Sharon Kirchner, owner of Career Strategies, a career counseling and coaching firm in Edina, Minn. "During my Fortune-500 career, I found that the people who move up in a company are the ones who can communicate their results and achievements, as opposed to just listing job duties."

Don’t hide behind your vocabulary. When your resume isn’t clear and to the point, the reader gets bored and pitches your resume in the trash.

Write as if you were talking to a class of sixth-grade students. For example, instead of saying "implemented," try "adopted" or "set up." Never "utilize" what you can simply "use." Don’t "interface" with people -- "work" with them. Instead of using "impact" as a verb, try "affect" instead.

Mistake #5: Errors in Spelling and Punctuation

Using your word processor’s spell-checker isn’t enough. You must read through the resume once for accuracy, checking numbers, dates, city names and other facts, a second time for missing or extra words and a third time for spelling.

Show your resume to several friends and ask them to read it out loud. Listen to where they pause; this could mean you’ve written something confusing or inaccurate. After you get their feedback, revise the resume so that it’s error-free.

Mistake #6: E-Mailing a Garbled Resume

Growing numbers of candidates e-mail resumes to employers, which poses its own problems. Your resume may arrive garbled and unreadable. If your resume can’t be read, how can you be hired?

While most people send their documents either as an attachment or in the body of an e-mail message, I strongly suggest that you do both.

First, send your resume as an attachment. Almost all e-mail programs let you send attachments, which are documents that ride along with your e-mail message. When the reader gets your e-mail, he can open the document you’ve attached. Save and attach your resume in rich text file (RTF) format, which is readable by nearly all word processors.

Attachments aren’t foolproof. They may get scrambled during transmission and become impossible to open. Or the reader may not have the same word processor as you, preventing him from reading your attached resume. Or you could run into the Mac/PC problem -- if your resume was written in a Macintosh format, it won’t be readable by a PC and vice versa.

To make sure everyone can read your resume, copy and paste the text of it into the body of your e-mail message. In your word processor, highlight the entire text of your resume and copy it into the clipboard. Switch to your e-mail program and paste the text into your message.

If you use both methods, you can be certain that one way or another, your resume will be read.