I don't bother with when rent needs to come in, because if it's not in my account 5 days after the first someone is getting a Notice to Vacate. That takes care of that record keeping.
I keep spreadsheets on each property mostly to keep up with tax information. I use 3 categories - mileage, meals, materials, and just drop the receipt expenses into each. At the end of the year I'll pull out of materials anything that needs to be capitalized (i.e. kitchen cabinets). My spreadsheet for each property more or less looks like this: date of item in Column A, expense in appropriate column B-D. Autosum formula at the bottom of each column.
I don't bother with maintenance; I keep up with repairs as necessary and most regular maintenance (i.e. cutting grass) is done by the tenant. If you keep up with all maintenance, or contract it out, you would probably want to have a spreadsheet for this. Just like with expenses, except you probably list the maintenance item in Column A (clean gutters, change filters, etc), and create however many Columns B-whatever as necessary for the frequency of the item. Then you can fill in the column with the date it was done, or if you want to calculate it for tax purposes, the amount you paid (where the headers are the months/weeks/days).
