Is there a min - max monthly contribution?

Bigger you go, the more you are going to need the correct vehicle or less investors are going to have contribute more capital.There are companies and people who will do the paperwork to ensure the active roles are documented and the legalities are followed.

Each partner contributed say $100,000 to the partnership to purchase the rentals. 

Can I use my Contributions (initial money earned, not money gained) in my Roth IRA to invest into a passive income without penalty?   

In addition, if you are self-employed with no full-time employees you may wish to consider opening a Solo 401k instead of a self-directed IRA as it has several advantages over an IRA LLC such as much higher contribution limits, direct checkbook control (i.e. no need to have the account at a specialty trust company), ability to take a 401k loan, exclusion from unrelated debt finance income tax with respect to investment in real estate acquired with non-recourse financing, etc.In addition, please note if you purchase debt-financed real estate with your IRA, unrelated debt finance income tax should apply to the income attributable to debt-financed real estate held by your IRA.

I went to a seminar (designed to siphon money from the attendees  I will admit... which I did not contribute to)... but I learned a lot of good information...and one of them was the motto, "Flip, Flip, Flip, Buy a Rental".  

I'm trying to figure how I should be going about offering on deals, and any insight would be helpful.I currently have about 100k in investible cash, my home is how worth about 160k, my 2016 and 2017 tax returns can support a modest 250k loan, my 2019 return will be significantly higher but I haven't filed yet at the advice of my CPA, I have ~150k in retirement accounts that I could access, and my parents would like to partner and are willing to contribute 100k. 

We were gonna go 50/50 into the deal where both of us contribute 50% of cash reserves for an initial down payment.

He wants deal flow, someone who knows how to structure creative financing (that's very hard to find in our market but I know how and, equally important, I know how to get them closed), and an equal monetary contribution. 

if the site has some contamination, you need to consider how to allocate that liability with both the seller and among the buyer group. did your BF business contribute to the contamination?