From what I read there is no law regarding what I may provide for an employment verification, as long as its truthful.
Is ther any law stating that I must provide employment verification? I get a lot of calls asking for verbal verification, and everytime I'm a little nervous about doing it. Sometimes the one asking doesn't even identify themselves, which I'm pretty sure is against the law. Any information on this would be appreciated.

No, with limited exceptions in DOT situations, no law requires you to provide employment verifications. I would do so, though, if you get a signed release from the employee.

That's one way to handle this, btw; if someone asked for an employment verification, tell them that you'll be happy to provide it as soon as they mail or fax you the release.