I would call up 3-5 property management companies and see what they would set rent at and why.

Just got home from 3 hours of clean up at a property today, in the cold and rain.

Or any tax strategies that I’m potentially missing out on by not setting it up in an LLC versus personal conventional mortgages?

Most investors are doing LLCs from my experience... but that doesnt mean you have to. there are some liability protections with LLC, along with a little anonymity if set up right. but also some added costs. one suggestion here is just whatever you decide, stick to it. some counties will see a transfer between personal/ LLC or vice a versa as a 'sale' and trigger property tax reassessment.  

I'd recommend you follow your favorite forum topics and set up keyword alerts!

Is it a unique setting? 

One had a client's cold water line crack in the middle of the night and flood the basement.

@Luke Masaschi it sounds like you've already got it set up! 

I'm just lacking the knowledge as far as starting the business off correctly as far as LLC's and being legally set up beforehand.

For the tenants that will occupy the empty unit in the not too distant future I can make my own rental agreement, in particular, I plan to let them pay for the water as well, and I will set a reasonable security deposit.But for the tenants in the currently occupied unit:1) Would it be possible to write an addendum to the existing rental agreement to require the tenants to pay for their portion of the water bill?