Here's an example of a bad resume with some things highlighted to show where it's gone wrong/needs fixing.
If yours looks a bit too much like this one, it might be time for a rethink.
Please feel free to share this to reach as many people as possible, because these types of things can seriously hurt people's chances of getting through to interview stage. Resumes need to have impact and convey value through skills/achievements and they need to do this within the average 6 seconds that a resume's viewed before hiring managers/recruiters either toss it to the No pile, OR decide to read it in greater detail.