I thought about this when I was getting all my documents together for this years taxes.Impact cost basis, how may I ask? 

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

I am looking at listings online, running my numbers.

I purchased my first investment property through an online auction for delinquent property tax.

Quote from @Obed Calixte: There are a ton of free tenant applications online and through property management software companies such as turbotenant, rentspree, zillow etc.You will want your application to meet any state specific guidelines (if applicable). 

What documents do they require, what credit scores do they allow, how do they verify previous rental history, etc.?

However, some lenders may have guidelines on how soon you can move in, so it’s worth double-checking if they have any seasoning requirements before converting to owner-occupied status.Refinancing Options – If your goal is to eventually refinance into a conventional loan or an owner-occupied loan, be aware that most lenders require 12+ months of documented 1099 income for qualification.

Never put all your eggs in one basketread the PPM and documents and have an attorney review understand what your investing in, fees and hold Timeunderatand their track record a lot more to consider those are just a few 

I do SMS, cold call, mail, online, wholesalers, etc.

@Andrew Moresi I have been looking around, I found a couple promising properties online and am also in contact with a realtor.