Contacting other landlords or management companies that are in your market can be hugely beneficial.

Few will show up or show me they are really financially ready.You want deal with serious people whom you will mutually benefit.

These numbers make so much sense.....the renters build my equity in the property long term while I get to pull 12% return on the cash i put down out of pocket.....If your'e familiar with many high quality mutual funds available in the marketplace, they average a 9-10% rate of growth.

In your experience, would it be more beneficial to get a HELOC with a lower long term rate (Credit Union) or a HELOC with an option of a lower 1-year fixed rate for the short term and a higher interest rate for the long term (Conventional Bank)?

Just questions to ask him as you explore the idea.In the end, just remember that the arrangement needs to be mutually beneficial (especially when dealing with family) and that literally everything is negotiable.Good luck!

Or wait and put my money in a mutual fund and wait to have more money to invest?

Depending on how things are selling and the income they are generating would depend on which is more beneficial.

(I think of it like this ... every dollar I don't spend on is a tool to be invested) I am building a taxable mutual fund portfolio (I think of this as my personal bank) that will buy properties 1 at a time.

I love being a private lender but the fact that it simply increases my taxable income makes me consider shifting some of my note portfolio to multi-family perhaps...You might find this discussion beneficial where similar question is raised: https://www.biggerpockets.com/forums/51/topics/604...Owning notes in your retirement account (especially self-directed Roth IRA or Roth Solo 401k) is ideal since you can have tax-free income for the rest of your life if you utilize one of these vehicles. 

Why is it so hard to understand that trading equity in Real Estate can be very beneficial and easily doable?