Looking for a good resource for an employee background check

I am hoping one of my fellow business owners could help me out with a little problem. I am looking for a quick and inexpensive way to do an employee background check on one of our employees. I know I should have done this prior to hiring him, however I didn’t. Although, my employee hasn’t given me any reason to not believe him, I really feel as though I need to make sure I am covering all my bases. In this day and age, it seems, as though you can’t trust anyone. So, if you know of a good resource, please let me know.