heather and brandon turner's book on managing rental property is a good one that helped me a lot with systems. sometimes you do not know what you do not know until you get started and can create systems that work best for you.

The newer ones continually have repair issues, mostly driven the electronic controls and complex systems to squeeze out efficiency. 

That's why it's called "systemic" and not "systematic" racism. 

I’d personally recommend staying smaller than 10-12 units while you get your feet wet on your first and build systems particularly if you will be self managing.

You own the system.

His invoicing is QuickBooks which is a good system snd cost money to have.

The whole foundation system is modular and installs in 1 day.We do meet state and city requirements and have approvals in Sonoma, Marin, and a few other counties as well as working to get approval for a primary dwelling in Mill Valley and Fairfax.The structure can be disassembled and moved easily because of how it's designed but it's far too big to be considered "mobile". 

The septic waste system will need to be connected to city sewer in the spring, which will run about $4200, and the house also needs a couple safety repairs/upgrades, which cost another $1500 roughly. 

I'll probably order Jeff Booth's book, though I'm betting the big systemic issues he's addressing are more likely to play out over a very long period-- throughout my grandchildren's lives. 

You can archive them on your cell phone to keep the logs if that helps.