Best way to document an OIG check for audits?

I do the OIG investigations by taking a screenshot along with the date of when I made the request; however, I am unsure this is the best method. Are you using good documentation practices for your OIG checks investigations, for example, keeping a list of search terms used, different name variations used in the name search, match resolution notes, etc.? Are you treating contractors and temporary agency workers the same way as you would an employee? My goal is to create a uniform and solid paper trail that can be followed if an audit were to occur, while at the same time avoiding excessive administrative work.