I have multiple properties and use excel to track income and expenses for my CPA.I put all receipts in a folder and put them all in my tax spreadsheet in January I have a rent roll spreadsheet that I track rental income, dates rent paid, lease dates, occupants, hvac filter size, trash days.

Download any apartment investing book to learn the language of NOI, cap rates, and debt service ratios.

This will help you "begin with the end in mind" (to quote Covey) as a key reason you will be tracking this information is so you (or your accountant) can do your taxes properly (but also great info to track to help you assess your expenses and financial performance).Seeing the actual Schedule E form you will fill out with your 1040 may help give you ideas on filing, the system, its organization (by area of expense for example, or all in one place) should you go with Excel, old school folders, or some other format that works for you. 

Download BP’s newest book here some good due diligence in Chapter 10.

If you don't have a property analysis worksheet yet, go download one in the FilePlace, under Resources here on BP.  

Then you can download this to Excel whenever you want to manipulate data. 

I have STR rental examples on my website along with a spreadsheet you can download that assumes a 10 year hold with certain appreciation and rental increase assumptions.

What are the pros and cons of having your documents for download on your website?

For tax filing, I bought TurboTax Download version, which can file multiple tax returns.  

I had one lady I visited who had all of my marketing materials from the last 18 months in a folder - some folks do actually save these things.