Excellent is all I can say.

I am NOT a US citizen but have excellent Canadian Credit and can get GC if it helps.

They were all excellent background material on Quickbooks but obviously not geared toward Commercial real estate.I have not yet purchased the landlordaccounting.com e-book.  

Tip:  It you are photographing holes in the wall, stick your hand or a ruler next to it to give an indication of the size. 

@Kenneth Vargas hope this helps you as a start.....Excellent info here...

I use that and an Excel spreadsheet to manage my finances.

REI is a excellent choice to achieve that goal along with building wealth.Bigger Pockets has various resources such as: ebooks, forums, blogs, webinars, podcasts, keywords alerts, an awards system, learn section, colleagues, informative people in many fields of real estate, and more.

Interacting in the forums is an excellent want to meet people as well.

You can do it in Excel with the financial functions, such as PMT, FV, PV, NPER, and RATE.When you're considering a loan with a balloon, you use the amortization period to calculate the payment.  

Ring Central is excellent.