Grab a couple of "example properties", get all your personal financial documentation together & get prequalified if you haven't already.  

18) What documentation do you require for the deal?

Have official loan documents drawn up professionally so they could potentially sell the note if they need the money suddenly.This may not apply, but if the money is coming from a retirement account you might run into some trouble since you're family.

Then you would want to be sure the contact is recorded on title and document everything including all payments.  

I am new to the area and looking for a real estate attorney to do the closing documents on a For Sale By Owner home.

The owner needs to give you two documents: P & L (profit and loss) for the past 12 months (the "trailing 12"), showing you all income coming in monthly, and all expenses per month.

That was standard, they wanted to see all your financial documentation, but I haven't used them yet so I am not sure how they are with closings.  

How loans should be:  Approve a loan with a specific buyer(s), seriously put them through all paces including tax transcripts, employer verification, account verifications for any downpayments, gifts, whatever they need for approving at their target price, all documents needed to give them total clearance for x amount for PI before they ever walk into a home looking to buy (with no change in income or debts, of course).  

Start with a blank document that is the same size as your postcard in Word/Publisher (4X6 or envelope etc).

I prepared a letter of explanation with the desired outcome of setting a call or meeting to discuss but before I send the letter out what other tips or documents should I enclose to showcase my legitimacy as a buyer and my seriousness specific to this property?