Your REIA will be a good source for one if you don’t know one.

If you're unconfident of identifying them, bring in an engineer.One of the biggest issues you'll run into is fire blocking.

So what you are saying is that as long as my tax return reflects the additional income appropriately then a lender would have no issue with using it as a source of income when applying for a mortgage?

The second and probably biggest issue with loan approval is that most underwriter's will spot that the property is leased out for another eight months and will stop the loan from going through as an owner occupied loan. 

So, I get in my car after viewing property, turn on an old BP podcast from 2016, and they immediately start talking about a purchase in Chicago at a 4% rule, and how it was the biggest headache ever and the money wasn't worth it.

Zillow for example has not managed to turn a profit yet since their launch in 2006, they are desperatly looking to add profit sources.

I hope other experienced investors can point us to single sources, but suspect the tools and knowledge is gained from many angles (books, podcasts, seminars, mentors, etc.) and experiences (successes and failures). 

I've found the biggest factor is proper pricing.

If they go for it, make sure your inspection includes turning on all water sources and checking outlets.

Do you know of any local investors in the area that would be good sources to connect with?