This is really critical, because you could pass up most motivated sellers if you take them at their word. 

I believe it's critical to start doing your own research.

Any advice or constructive criticism is greatly appreciated!

I think this is critical to giving you the best possible advice.  

Don't skip this step, as it is critical for banking, obtaining loans, and for defining the terms under which you and your partner dissolve in the case of a disagreement. 

Permission from the seller is critical.  

Understanding the difference between an "expense and a cost" is critical, and the difference between "getting there first, and getting what's left".

You will see they are investing in the strongest markets, have great broker networks / access to deals which is critical in a highly competitive market, can raise significant capital to take advantage of scale, more disciplined / conservative underwriting models, have simple well thought out business plans to increase the properties value, using fixed rate 10yr loans to take advantage of still incredibly low rates historically speaking and use more sophisticated tool sets to help understand how fluctuations in occupancy, rents, etc may impact their models.  

Always be sure to take some of the biting constructive criticism and recommendations with a grain of salt.  

He has a good track record, but I have never lended money so I'd appreciate any guidance in how to set the terms and what steps are critical to ensure the relationship doesn't go south.