How many previous jobs should I list on my resume?
Is the standard amount to list 3?

Yes the standard for a resume is 3. However, if you hardly have any job experience then I would list them all.

You should list all that relate to what you are going for. If it will take too many pages, then briefly describe each one in a section called Job Related Experience and in a short sentence tell what you did to either save money or make money for the employer.