Best ways to legally arrange a relationship with your investor

[Rob Ko]

Hey guys, I have an investor who is willing to invest some money into my projects. I would provide a down payment and bring the deal and he would finance the rest via morgage. 

What would are the ways how we could legally arrange this? Create a LLC or ...

Also, those of you who already went through similar situation what is usual split. 50:50? 

I would greatly appreciate your input and your experiences. 

Thank you very much!!!