Some random advice and life lessons...
Cheryl C. I have lost lots of money and learned many lessons. Since I would hate for anyone to lose hard earned money here are my thoughts.
#1 Make sure that the person has been in business for awhile.
#2 Request documentation! I would like to see the LLC operating agreement and auditor reports of all properties in LLC name. Maybe credit lines from banks as well. Ask for before/after pictures of properties with financial details of reno costs, expenses and cash flow. Ask to see lease agreements.
#3 VISIT the area meet your potential partner and see how the "machine" works in person. My version of investing and houses are probably a lot different than others on BP. You need to find someone that you are comfortable with and invests in properties that YOU feel comfortable with. Flying out to meet a potential partner is the CHEAPEST due diligence you will ever spend! Better to be out $800 than 50k!!
#4 I would ask for first lien on the property to secure your investment. It's sad but LOTS of people are more interested in scamming money at least you have some protection.
Hope this helps