Note: These are fee based services.
More Info:
What is a background check?, What information will be in a background check?, Who runs background checks?, How do I run a background check?

What information will be in a background check?
A background check will include information that is obtainable from public, government, and private records. It will commonly include birthday, any aliases or maiden names, records of marriage and divorce, addresses and phone numbers for several years, information about neighbors, relatives, and known associates. It can also include information about property ownership and home valuations, as well as other financial information such as any liens or bankruptcies or any other lawsuits. Some background checks will also include information about criminal convictions and specifically sex offender violations. What information is available will vary from state to state.
Who runs background checks?
Background checks are run for many reasons. Employers commonly will run employee background checks on job applicants to verify the information on their resume and to make sure that information has not been withheld. Apartment managers or those renting out their property will often do background checks on their potential tenants to check for red flags or problems. It is even becoming common for families to use background checks as a solution for checking on nannies or babysitters or other contractors they are hoping to hire and that will have contact with members of their family. As more people connect over the internet it has also become common for people to do background checks on people they've met online or through dating sites or other blind dates.
How do I run a background check?
There are many ways to run a background check on someone. What you do will depend on what information you need to know. There are many public records websites available online that will allow you to look up the publicly available records regarding a person. There are also state records available online to search as well. You can also pay for a third-party professional to do the background check for you since the information in a background check is often protected by different state laws and also is not always accessible to everyone.