As @Lee Ripma mentioned "Set For Life" would be a great book to read.As far as choosing the right market... you can read several reports online (just search google for XYZ city real estate report).

I’m looking to open an online account with vanguard, TD Ameritrade, E*Trade, or maybe even the Robinhood ap with my checkbook sdira to buy REITS.

I have been looking around, but I would love to go to someone with high reviews by other investors.

Can anyone recommend an easy to use online payment app or method for allowing tenants to pay online and direct to my account?

Lease docs, contract docs for when our clients buy/sell houses, anything we need signed is done through there.Giving tenants the ability to pay online or with a card.

I've done a lot of research on it online, which is possible here, and even gone to see it (pretty recently renovated!?).

My issue-situation-question is this: Because we have made REI our goal, with a plan for a lifestyle change, business objectives , and everything, we are online every day looking for and analyzing deals [as you can see I upgraded my BP account to have full access to the calculators!!!

@Martin Robertson Hi Marty,QuickBooks Online Plus - you will need one subscription for each EINQuickBooks Desktop - depending on your need Premier, Accountant or Enterprise versionsGita

There are great services out there that assist in marketing your property, creating online applications and screening your tenants for you. 

I'm having an attorney review them and my rental application for compliance in my state.