Can anyone help a freelancer on some advice?

Guys, can anyone give me advice on freelancing? I am free lancer that works with a company to build product they assign to me, and then they pay me money. But there is no Physical Documentation of it. How should I guide through this? I want this to be on my Resume this should count as a work experience right? I have developed 7 Programs for them until this point. I have been working since July.