Then I heard about Quickbooks Online.

If the Appraiser chooses to include converted living spaces as GLA, the Appraiser must include an explanation detailing the composition of the GLA reported for the comparable sales, functional utility of the subject and comparable properties, and market reaction.”I am a layman on this matter, nonetheless this is my interpretation: Unless this "4th Bedroom" has a permanent heat source, is completely finished out according to spec with the house, and comparable to neighboring properties with finished basements, then there is a good chance it will not appraise.

And Sec 1031 if you held the property as an investment you can sell and purchase new property using the 1031 process and indefinitely defer payment of the tax.Without one of those two exceptions you will pay tax no matter how long you own the property.

The appraisal shouldn't matter, as it's the down payment of sale price.

There are so many great free educational resources online on the details of flipping (and saving on taxes), and even more on straightforward rentals.

The most important thing you can do is to hook up with investors in your area to learn your local laws, closing attorneys (or title companies), how to buy, investors you can sell the wholesale deals to, etc.Reading online is a great back up, but you must connect locally.

Plenty of samples online; tailor to your transaction.

@James LeeHow much cashflow you’re willing to take should have your expected appreciation playing a big factor, no matter what it is

Civil matters are just that, civil between a tenant and landlord.  

You can view it as savings, cash flow, or a $650 mortgage payment, doesn't matter.