I use http://www.youcheckcredit.com/ to check for credit. You need to register as a landlord first. They have many packages for background check. There’re standard rental application and lease agreement forms from the internet. I use the ones provided by California Assoc. of Realtors (CAR). Depending on where the applicants from, there’re free court searches for both civil and criminal records. In SD county, http://courtindex.sdcourt.ca.gov/CISPublic/enter?_pageid=55,1056871&_dad=portal&_schema=PORTAL . I check this first, before wasting money on credit reports. There’s also a useful website for these type of questions. http://www.biggerpockets.com/forums/52-rental-property-questions-landlording-issues

Good luck.