What are my expectations of Property Manager?

[Steve Spencer]

Over the past 12 months I've built my portfolio from 6 doors to 30 with my most recent acquisition being a 12 unit building.  I am now to the point where I need assistance and researching my options of just hiring a PT maintenance person or hiring a Property Manager to oversee it all.  If I hire a PM, what are my expectations?  What is the general role of the Property Manager or does anyone have a "job description" they could share.  What kind of contract should I have with the PM?  In my area I have researched and noted 10% is typical but what all should I receive for that 10%.  Thanks for all of your feedback