How do I handle a long gap on my résumé?

I have been out of work for 13 months and worry about the gap. Any experience at all would help. I am not sure how much to explain. How did you handle it on your résumé?

I listed the volunteering and course under the same dates and kept the explanation to a sentence in the cover letter.

Thanks for writing this out. I went through something close to it 13 months ago, and it got easier once I kept a simple log of every call and form.