INvesting in a family member's project

My family member has been a designer builder in a college town in the northeast. He has an opportunity to buy 6 lots in the village on which he would build to suit future homeowners. I would like to invest in his future as well as make some return on my investment as I am newly in retirement.
1-If I invest the money to buy the property, what is the usual way this investment pays out to me?
2-What protects my investment?
3- Are there informative articles that would helo me understand this a bit better?

Best way in the world to lose friends is to get them involved in a financial situation which FAILS to pay off as MUCH as they expect.

Then on the other hand it turns out to be a bonanza…he will be UPSET that you got all the $$$ and DID NO WORK.

In one word…NO.

Family and business is usually not a good formula. That said, you putting up the land and letting the builder do what he’s good at is not unusual in new construction. You can split the profits in any way you see fit. Typical arrangement is 50/50.