I'm trying to find someone that can fill the bookkeeper role we just had open up. 

It can be done with comingled funds, it would just cause a lot more bookkeeping and classifying of charges between "business" and personal.

Let's say, it costs you 1.5K to get your structures in place (holding LLC or Series-LLC, with or without land trusts, with or without separate operations LLC) and 0.5K per year (for maintaining the LLC properly, bookkeeping, lawyer and CPA, etc.) for a total of 2K.

For that business, I like it and it suits my needs.Our bookkeeper for the rental business is retiring.

@Chad Hedgepeth The best thing to do is let the experts do their job, so get a lawyer that specializes in RE to help with your entities and a CPA that specializes in RE to help with tax matters.I'm a CPA by trade and I STILL hire out my tax/bookkeeping work. 

Or, is it management by committee with one person doing the leasing, another person handling the maintenance, another person handling the tenant issues, and another person handling the book keeping?

Focus on building your business and leave the tedious tasks to your bookkeeper or accountant.

QuickBooks is kind of a common bookkeeping and accounting platform. 

I'm curious to know what your biggest struggle is when it comes to bookkeeping and/or finances.

In my experience cash is ok as long as there is a deposit receipt or bookkeeping to go along with it.