Worry not, I do plan to speak to a wholesale strategist BUT I also plan on obtaining a RE license (which includes attending the necessary classes), RE and business advice from a legal professional, tax and bookkeeping advice from the proper professionals.

For example starting payroll, filling W-9 for independent contractors, tax rules, bookkeeping e.t.c?

He works with Real Estate professionals and offers full service such as bookkeeping, tax filing and preparation, and etc.

The best way to ensure correct filing is to have accurate bookkeeping and records.

You really only have to have one bank account as long as you are crystal clear with your book keeping with each series. 

Franchise Taxes, Secretary of State, IRS Filings)Lawyer, Accountant, Bookkeeper...and you'll need a special evaluation process for YOUR country based on the US Tax Rules/Israel Tax Rules and Currency Exchange Rates.As you can see, going this route is not easy but doable. 

Wanted to see if anyone has some tips for simple and effective bookkeeping for buy-and-hold rental properties.

FaqID=161&C..."...no licensing is required if the business is hired to maintain the grounds, collect rent or perform bookkeeping services but will not be showing property or negotiating leases."

You're going to need a real accounting system and probably a bookkeeper to keep it all recorded if you're operation is that large. 

Whatever and whoever, you may decide to select as a Tax Accountant and or bookkeeper, be sure to inquiry it they have a separate BACK UP system for your accounting information.