What do you do if you have had breaks in your employment history for various reasons such as health and returning to school and self-employment?

Put them with your job history. The school, put with the education section, if there is an education section. You need to list everything from the time you started working until now. For health reason, just put the dates that you were sick and say off work because of illness or poor health. Or something similar. I wouldn't put what you were sick from. It's not their business and it doesn't matter anymore. For school, put it in the education section or just list the dates in the work history section and put the name of the school and what you went for, awards you received, if you graduated with honors, etc. For the self employment put the dates and the name of your company. If you didn't have a name, put self employed. And then list the type of job and all of the duties you did while you were your own boss. Bookkeeping, calling customers, scheduling, anything that you did for the job.

Be honest with your answers. "As you can see by my resume, I was pursuing additional educational opportunities." Or, " I had the opportunity to be my own boss for awhile and now I am back in the job market for more knowledge and experience within the xyz business and the changes within the field" If it is health related, I would suggest that you just state that you were spending time with family or something noncommital. If you answer because of a health problem, you are opening yourself up to additional questions about the cause and further future issues with the illness.

In my experience, breaks need only be listed on your resume. I have had several interviews in different industries and the employer usually will refer to the resume for such information rather than ask point blank about it. Don't worry about breaks less than 2 months. Some people just want a change and it takes them a while to find their new niche.