I would prefer electronic payments, but I don't have tenants who know how to use the internet very well.

If it;s one of those big old electronic lockboxes take the serial number off the side and call Supra to see who it belongs to.

Now I usually just do everything electronically.  

One thing I learned on here was using Cozy.co to collect payments electronically, can also report rent paid as a positive trade line.

Mint automatically tracks your electronic purchases and classifies them by type (food, gas, housing, etc).It seems like right now that you are trying to build a budget without knowing what your historical spending pattern looks like.  

Various kinds of electronic locks on the front door would serve a similar purpose. 

Some local boards will allow you to be a "member," pay annual board dues, get access to the MLS, and subscribe to the electronic key service to view listings.

And finally it says that you can advertise the property and/or your contract by way of: 1) signage on the property; 2) electronic or print; 3) listing it on the MLS.

As far as all the documentations, contracts, receipts of each properties, do you guys scan them and store them electronically?

My town has electronic water meters that provide the city a lot of info so they are able to see when something like this is happening.