Whether you are looking for your first job or a new job, you will need a résumé. Dictionary.com says a résumé is ...
a brief written account of personal, educational, and professional
qualifications and experience, as that prepared by an applicant for a job.
A résumé is basically a summary of your skills and a history of where you have worked. It should describe your education, whether you finished high school, have a BS or a BA, have a masters degree, or maybe even a doctorate. I think most people who hire other people to work for a company (or any establishment that has employees) use a résumé as a screening device. There are no doubt computer programs that read résumés by the hundreds, looking for key words like "writer", "carpenter", "bilingual", or whatever they are looking for to fill a position. For that reason I have had to remove details about being a computer programmer early in my career (I am now a technical writer). Job sites, like CareerBuilder.com, will send periodic lists of jobs to your email address based on the résumé and profile you have submitted.
Humans who read résumés also scan for key words, according to my wife who was once a Human Resources person at Apple Computer. HR departments get stacks of résumés when they post a job and even when they don't. People like me go to the websites of local companies and submit a résumé even if they are not posting any jobs that are right for me. Who knows, something might pop up in the near future and they already have a qualified candidate -- me. I would bet most companies dump those submissions fairly often, so you might have to reapply occasionally.
If you have never created a résumé, there are people and services that can help you do it, and many of them are free. You might even get a friend (especially a writer) to help you create a résumé or to, at least, review and edit it for you. I would suggest that you not go overboard if you are looking for your first job (I'm not even sure McDonald's or Burger King require a résumé), but some expense might be worth it if you are looking for a highly professional job.
There are many résumé styles, but most are either chronological or functional. The chronological format actually lists the things you have done in reverse order. In other words, it lists your most recent job first, then the previous job, and so on. Then is lists your education and any other activities (like clubs and hobbies, if applicable) that you are proud of. This format is good because the person reading it can read as far as they want and stop. I have recently been told that you should only list job experience within the last 15 years. This is good news for older job seekers. I have no doubts that at least some résumé readers screen for age. Listing only your most recent work details may get you by that screening process.
The functional format presents your skills and accomplishments by grouping information based on function. This format highlights what you have done, not where and when you did it. The functional format might be better for first time job seekers or people who have gaps in their employment (like staying home with your new baby for the last several years). Of course, the company to which you apply will most likely have some sort of application form that requires places and dates that you have worked. So have that information handy if it is not in your résumé.
Some job seekers create a résumé that targets a specific job or position. This may seem a bit deceitful, but not really. The targeted résumé simply saves the reader time because he or she does not have to read about all the wonderful things you have done that have nothing to do with the job for which you are applying. For example, there was a time that I was just as adapt at computer programming as I was at technical writing. I could have had a résumé that targeted programming jobs and a résumé that targeted writing jobs. The targeted résumé can be formatted either chronological or functional.
No matter what style (one column or two) or format (chronological or functional) you use, you most likely need a résumé. Do some research online and see if you can find examples of résumés best suited for the job you are seeking. If you are just starting out, you can even ask people who interview you what they are looking for in a résumé, and whether they could make any suggestions on your résumé. Most will be glad to help.