Another mistake people have is that they ask for money or ask people to sign off on a loan on their first interaction.

A good comparison can be found at Interactive Brokers.

Studies conducted showed that when there is an equal balance of negative and positive interactions, the relationship is doomed for failure.

The property management company explained to me that they believe he is not liable because when he did the work he never interacted with the pressure valve since it is not located near the igniter that he replaced. 

The success of a big center like that is the property management and how well they interact with tenants and maintain the center. 

Again, the BiggerPockets store has some books for this or you can learn by watching podcasts, reading blogs, and interacting on the forum.

If not buying a multifamily you need to find the right lay out to interact with tenants as little as possible.In regards to resources, check out meet ups in your area and connect with locals you'll find the most common use strategies and you can start narrowing down your options. 

There was a lot of learning and fine tuning of my system/process along the way: make your listing as accurate and transparent as possible - are bathrooms shared, is it noisy at night, what is unique/peculiar about your place, what is provided for guests, what is kitchen policy, how many nights is an ideal stay, how will you be interacting with guests etc. 

So much knowledge and interaction.  

The best description Ive encountered is that most people GET energy from interactions with other people, where by introverts have to USE up a lot of mental energy when interacting with people.