Private money loan to investor for property in California

[Myriam Keaton]

Hello,

I have a lending opportunity coming my way. I'm new to this and I'm not sure of all the precautions I need to take, apart from running the numbers on the property, and working with an investor who has a solid track record (which he has) to make sure this venture is successful. 
I would be a second lean on the deal for 100k

What do I need to know or what actions/precautions do I need to make in order to take an informed and educated decision? 

Thanks!