The longest I remember which is what all my transaction records is 7 years, there are 1 year and 3 years, but I told my bookkeeper to keep everything for 8 years (except those that need to keep permanent like incorporating papers, EIN filings, etc) to be on the safe side.

If you have a bookkeeper and is OK taking that extra cost, it works, but for me, I want it just like Quickbooks, where I download and tag the transactions and done.3- I found that their online leasing workflow to be top notch.

It is designed to handle everything including the bookkeeping for the properties.  

I am looking to connect with other investors in the area, but am also looking for recommendations on a bookkeeper/accountant that understands rental properties.

Daily, weekly, or when the notebook starts filling up, take each receipt and either file them or add them to your bookkeeping spreadsheet.

I use it for my CPA practice, tracking income from different sources to help me measure, budget and anticipate, and we use it for all of our residential and commercial investments (separate company from the CPA firm) QuickBooks does all the debits and credits without you even realizing you are doing debit and credit bookkeeping.

Although I've never used their property management services, I have used "BSU" - Business Services Unlimited, for all my bookkeeping for 2 of my 3 businesses over the years.  

I also have a bookkeeper and accounting firm for all of that. 

I forgot to mention I work part-time on the side with a real estate investor who does tax prep and bookkeeping for other real estate investors.

My greatest strength is that I'm a bookkeeper, I invest in the market, I save most of my income and I have a excellent credit score.