We have two rental properties and use a Property Management Company. They charged $500 (in 2009) and now $750 once a lease is signed. This covers all advertising, credit checks, etc. The monthly management fee is 10% of the lease price. There is a $250 lease renewal if the current tenants choose to extend.
Having the management company handle the rentals has been overall great. They handle everything and call us only when there are issues that need repair that are over $100. We have never had any contact with the leasees of either property and one home has been rented for 2 1/2 yrs and the other for 6 months. The management company deals with screening all the applicants. We set our criteria (no pets, etc.) and then we get the apps for qualified candidates. We then make our choice. The management company assumes the responsibility for notifications, HOA non-compliance, and if needed evictions. They inspect the property yearly.
The negatives are that our agent has been replaced a number of times. There is high turnover at the management company and several repairs were made without us being notified. They are to notify us of all repairs but only need approval over $100. On our last yearly statement there were several small repairs that we had not been notified of.
Overall, we will continue to use a property management company (especially as we live in a different state now than our rental properties).