I have 6 houses and consider myself a novice. 

Quote from @Melissa Stanley: This is a tough one.

I would MUCH rather pay hourly for my pm instead of a % of rent.

Quote from @Christin Dorfling: Im North of Phoenix South of Flagstaff.

Having any kind of debt keeps you up at night;2.

Have them send you a line by line item of what's needed.

so, it could be ( am throwing out random numbers) a purchase price of $350K with $10K down, and then 30-year amortization at 6.5% with a balloon payment due in 5 years. 

As you are partnering with your sister, have a legal document drawn up as to what happens if one of you wants to sell and the other doesn't, how expenses will be split along with money you are putting down, borrowing, profits, etc. 

I paid about $1,500 for the installation of a high-quality 4-security-camera system, which can be monitored by both the tenants (and you!)

Quote from @Hemed Tov: I would really get with someone in that market that can dig in see what is going on with the market (comps), and also maybe the rehab was not as good of a job of what the market is yielding at 300K property.