Your resume is a "snapshot" of you, your qualifications, and your knowledge, skills, and abilities. The purpose of a resume is to give a "down and dirty" quick look at your background to see if it relates to the position you are being considered for. Putting too much information on a resume is almost as bad as putting not enough information on a resume.
Can you honestly say that your resume is a masterpiece? Not too many people can. Most resumes that I see are drab, boring, blah, and either full of useless information or inadequate information. Whoever is reading your resume might have less than a minute to do so. Do you believe you make an awesome impression of yourself with your resume in less than a minute? Remember that the person that is reading your resume has probably seen numerous other resumes over the course of the day, the week, the course of the interview process for a specific hiring process, and over the course of their life. The point I'm trying to make is that your resume must be able to promote all of your knowledge, skills, and abilities in a positive, unique and refreshing way that is different from all of the other candidates.
MAJOR HEADINGS (SECTIONS) OF A RESUME
I believe there should be no more than about five (5) major headings or sections contained in your resume. No more, maybe one or two less - depending on what you have to offer. Some of the major headings I believe in are your objective, experience, education, community service / volunteer work, certificates / licenses, and/or special skills and training. Let me discuss each section in detail:
A one-line description of what position you're going for and with what agency. Some people say you don't need an objective. I disagree. By listing the exact job title (taken from the job description) and the agency you're testing for, I think it shows a little effort and personalization. Listing no objective is almost as bad as listing something like "to become a firefighter (and nothing else)." That makes it look like you use the same resume for every department. A little effort can go a long way. Also, stay away from objectives that are three to four lines long that sound like a story with no obvious ending. I've seen ones that say something to the tune of "to obtain a position that will allow me to utilize my knowledge, skills, and abilities to be able to serve the community, and so on, and so on, and so on