A lot of my experience in my field (programming) is volunteer or contractual work. For example, for a couple of years I volunteered at my university to mark assignments, on a couple of occasions I've done guest lectures. As for paid work, tutoring was the norm. Considering the difficulty in verifying a self-employed position, is this kind of experience disregarded when a potential employer is peering through resumes/CVs?
A somewhat related addendum: I own a business unrelated to my field. Putting this on a resume shows some regard of leadership, accounting, etc and other clerical skills that would be useful in any occupation. However, it is considered self-employed and has the same aforementioned issues. Is it worth putting this on a CV? Of course it's wise to put it on a CV/resume, but I'm not sure if it would make as large an impact as I would like to believe.