If you haven't done so already, make sure that incomings and outgoings to do with the properties are dealt with in a separate bank account from the one you use on a day to day basis, and to which your salary is paid.
This makes things so much clearer.
Also means that you can very easily see if you're running at a loss (some people are in denial these days!)
Annual income twenty pounds, annual expenditure nineteen nineteen and six, result happiness. Annual income twenty pounds, annual expenditure twenty pounds ought and six, result misery