So you've purchased your investment property and now the cash flow starts rolling in, right? Not always; income-producing properties can be a great way to build your financial portfolio but experts caution: You can't buy them and then fall asleep on them.

Apartments, condominiums, duplexes, single-family residences and office buildings can all beef up your financial portfolio. But as with all investments they require attention and sometimes considerable maintenance.

No matter what size property you're caring for, managing it can mean calls at all hours of the night, relentless requests for property issues to be handled immediately or sudden vacancies, not to mention, the litigious society we live in can cause ample headaches for investors.

That's why many investors are using property management companies to lessen the risk, "When you're investing in rental property these days it's not just an investment like stocks and bonds. It's more of a business that you're entering into," says attorney Ted Kimball of Kimball, Tirey & St. John Law Firm in San Diego, Calif.

Kimball and his partners represent hundreds of rental property owners and managers. He says property management has really flourished over the last couple of decades mainly because there are numerous legal considerations to be aware of when running this type of business. "The ownership of rental property has become so risky from a liability point of view that it makes sense to have property management," explains Kimball.

"When I first started practicing law in 1977 there were many of our clients who managed their own property," says Kimball.

But not anymore Kimball explains, "Now it's very rare that clients or owners will be representing themselves in any action and many more owners have gone to property management to help manage the business of owning rental property."

Richard Wenrick, co-owner of Trilar Management Group in Carlsbad, Calif., says there are several benefits you get from hiring a property management company. They include assessing the best possible rent for the property, calculating accurate income and expenses on the property, staying current on the legal environment and maintaining the asset.

Deciding to bring on a property management company is only the first step. Finding the right company that's aligned with your goals for running your rental is the next critical consideration.

There are several questions and issues to ask and discuss with a management company before entering into a contract:

• How long has the company been in business?

• What types of properties does the company manage and in what geographic locations?

  "They might be a great company but they might not really be the best company for your four units in the city for instance, if they only manage in North County," says Wenrick.

• Discuss the management company's style of managing rentals.

  "Everybody says 'Hey I want my property to be the best in the world.' Well the best in the world may cost a little extra and they may not feel comfortable. So you really have to make sure the goals of the owner and the management company are on the same page," cautions Wenrick.

• What accreditations does the company have?

• Is the company a licensed Broker and do the employees, such as a regional supervisor, have real estate licenses?

Determining if property management is the right investment for your rental is an important decision. Kimball says keep in mind that "there are just so many issues now that can be sprung on a more or less innocent owner who just thinks the rental is a good investment, I think to protect that investment you really do need a property manager."