Despite conventional wisdom, you do not want to start your job search with a major resume effort. To do this puts the cart before the horse. A resume is really a kind of ad or brochure. Before developing an ad campaign, an advertising agency carefully targets its market and defines its customers' needs and priorities. Only after identifying these factors, does the copywriter describe features and benefits most useful to the targeted market. In your case, you are the product. You bear the responsibility of selling your most important experiences and attributes to potential employers on a person-to-person basis. If you write your resume before you have found out what they need, you are missing an opportunity to present your best case.

My son is now an "entrepreneur." That's what you're called when you don't have a job.
Ted Turner

Tailor both the resume and cover letter. How many times have you heard people say they customize their cover letter, but send the same resume to everyone? Usually they are very proud of themselves for doing this, as many job seekers send one form letter and resume to everyone. Unfortunately, when a resume is competing with 200 to 400 others, it has to stand out from the crowd. Recruiters don't have time to separate the "diamonds from the dirt" in the 10 to 60 seconds they spend skimming for relevant experience. It is the candidate's responsibility to sort the valuable stuff from the extraneous, using only 20-carat material to land an interview.