Any key concepts should you be sure to understand? 

I understand the concept well, but am hoping that people can share their experiences with it.

For business thoughts, theories and concepts I recommend "The 10X Rule" by @Grant Cardone, "Never Split The Difference" by Chris Voss, "The 4 Disciplines of Execution" by Chris McChesney and Sean Covey and of course the classic "The E-Myth Revisited" by Michael Gerber.

They both are smart kids and the big words/concepts will be a good discussion for all of us.I am planning on opening an account at a brokerage firm for them invest their own money and let them pick the stocks, but I want them to read about the stock market.Does anyone have a good recommendation of a book(s) that they had their kids read or is simple enough for a teenager to understand?

Sighhh.. and this is why all you folks are struggling with lead gen.Wrong concept all together.Here is why.You are not targeting "millennials" as a REI.You are targeting HUMANS.

I think the main concept you bring to front is what works for us at this moment being knowing on the back end that it may or may not save is problem I'm juggling with. 

I am asking this question of those who have done commercial deals and can explain the concept to me.  

@Bill Brandt: I believe you are misinterpreting the IRS's concept of a disqualified person. 

Given your interests in engineering related disciplines I would focus on financial engineering concepts and financial efficiency. 

You want at least a 30% margin above costs and the NOI needs to be enough to pay the debt service after stabilization and then some.If the project looks feasible from a financial standpoint the next step is to check with the city or county planning and zoning department to get an idea if your concept will work, if you can build what you would like to build and what is required for all approvals including site plan, building permits, proffers, water/sewer tap fees, bonding requirements, inspections, setbacks, lot coverages, parking requirements, height restrictions, C/O process and time frame for all approvals.You also need to check with the utility companies and get an idea of availability and cost estimates from them for water, sewer, power, gas, cable, installation and connection requirements, tap fees, hookup charges, transformer location and relocation, power line and power pole relocation issues.