The short answer to that question is as many as the number of jobs that you are seeking. That doesn’t mean that you are fully rewriting your resume each time you apply for a job. It means that you are starting with your basic resume and customizing it to optimize your attributes for each particular position.
I recently had a client that was the lead therapist for critical care at a large level 1 trauma center. She was transitioning into several new areas – each required a different focus for her resume. She needed a CV for a national teaching opportunity, a resume for a PRN position that focused on her basic skills as a therapist, and then finally, a resume for a program director position in a large corporation that merited an emphasis on her leadership skills, teaching skills, and ability to create new programming. The CV would not have showcased her talents sufficiently for the PRN or director position. The program director resume would have landed her in the “no” pile for the PRN position (overqualified) as would have the PRN resume for the program director (underqualified). Yet, she is the same person in all of the documents….just with a different emphasis on her skill set.
The point is that her focus was on the specific requirements for each position. I used the keywords/requirements for each position to highlight the appropriate skills which identified her as the ideal candidate for each job. By the way – she was offered all the positions that she applied for.
It is not misleading to highlight your qualities that an employer is seeking. It is your job as an applicant to shine a light on the qualifications you have and why you stand out as the best candidate for the job. It is also unnecessary to include details of your work experience that do not apply to the position. If you are over-qualified, an employer is likely to pass on your resume due to fear that you will quickly move on when a position comes along that better fits your qualifications. If you an under-qualified, you will not be considered. Having your basic resume at the ready allows you to quickly tweak it for interesting opportunities that drop in your lap (because you are doing such a good job networking!). A generic resume will not shine above the others so make sure you customize each resume that you are sending out if you are changing career focus.