Resume/job app question

I have a question about when you are creating a resume and when you are putting a job application in. What length of employment is acceptable to omit from a job app or resume? If you worked 2 shifts for a company and decided to resign, are you obligated to place that on an app? Also, what's an acceptable way to put only relevant job experience? I really don't want to put my fast food experience on my resume for a nursing position. :-)
Thanks for your input!
A good rule of thumb is to only list jobs held within the past 10 years on your resume. If you have a lot of brief jobs that you did at the same time (for instance, while going to school) you can always cluster them under one heading called "temporary jobs" and provide a general description along with a notation like "detailed information will be provided upon request". When a prospective employer does your (mandatory) background check, it will pull up any jobs where FICA witholding was filed for you. If this turns up an employer you did not list, you may have some 'splaining to do. If the length of employment was very brief, they may not have even processed any FICA, so you may be OK.... use your own judgement on those.