For instance, I once asked a family friend to loan me some money for an investment property.

As others have suggested, keep researching, reading, and even meet up with someone you know (friend or family member) that invests to see if they will let you shadow them through a deal or two. 

I have a friend in the Detroit Michigan area that is currently doing a lot of flips.

If you don't have multiple "REAL" private money lender individuals cash or 401's, It's impossible to SCALE and really grow. 

But have an investor/realtor/property manager friend that would probably be a good fit for you.

I'm known in my market as an investor-friendly Realtor, and people bring me deals based on this reputation.

For newly constructed, purchased or renovated properties and also retroactive generally over the last 10 years, building components are properly classified into individual units of property and accurate recovery periods for computing depreciation deductions.

Where have you successfully found reputable, investor-friendly lenders in the past?

An investor friendly agent can do all sorts of helpful things, like setting you up with a search for properties or connecting you with folks who have recently done deals like the ones you want to do. 6) Consider analyzing a deal or two in your local market, just for practice, with a free use of our Rental Property Calculator (or other calculators).

I have joined my local REIA and will be attending meetings next month, I have a relationship with an individual I trust (an older relative) who has offered about 150-180k to invest with me for my first deal(s) at a reasonable return, and I have started analyzing deals.