Have you ever heard of the '60s soul group the O'Jays?
Perhaps you're most familiar with their song Love Train -- which has been covered by everybody from the Rolling Stones to Diana Ross -- and even the kid's group The Wiggles. Another O'Jays hit from the '60s was a song called "Give The People What They Want," which was a cry for social justice from an era when many Americans were calling for equality and recognition.
The lyrics themselves aren't too applicable to fixing your resume, but the title is right on target. When you're applying for a job, give the hiring manager what they want ...to read.
In your case, what the hiring manager wants is a detailed description of your education and experience that applies directly to the job for which they're trying to hire. Nothing more and nothing less. This idea sounds pretty elementary, but you'd pretty surprised at how many resumes I see that violate it.
Who told you that you had to list everything you've ever done on your resume? The more detail you include on your resume that's not completely relevant to the job or sector in which you have interest, the more you're going to distract the reader from seeing all your great virtues.
Remember: Your resume isn't your permanent record -- it's a marketing brochure about you.
So how do you figure out what's relevant to the reader? In many cases, you won't. That's why you'll have a single general resume that lists your most important (to you) real work experience and the volunteer work and activiities about which you're most proud.
But you're also going to use the magic of word processing to shape, customize, grow or shrink your experience whenever you do have any inkling about the kind of details the reader may want to see. You might finish your job search with 20 variations of the same resume, each slightly different than the other. You might even end up with categories depending on your interests -- "This is my marketing resume," "This is my non-profit resume"...etc.
Whatever your approach, just make sure you're trying as hard as possible to make the O'Jays proud.
Next up: First Resume Mistake #5: Too Long