I started my first company in Houston TX, with freelancers doing different things in my company. Such as Virtual assistant, graphic designer, content proofreading and online publishing. They were one big reason for my success. I still use some virtual assistants for different tasks. So coming back to your question it is possible to do it but you have to take some precautions. I will list and explain few things that are essential below.
1- Make sure you have a agreement - that describes exactly what they are being hired to do, terms and conditions that you have, how payment will work. This will save you a lot of hassle if you put all expectations down in the agreement.
2-Rights to your work - Make sure you have a clause in the agreement that they are being hired, specially in United States. Example: the freelancer designs a logo for you for your clients. unless the agreement says so you technically do not own the product.
3-It is easy to think once you have been working with a freelancer for a while to slack of on the details. since they are not regular employees. you need to provide them with as much details as possible.
4-Unless the freelancer is working with you full-time, he might have other clients. make sure to have detailed timelines for each project.
5-When hiring a freelancer ask for a portfolio and past work they have done, another thing is to ask them how many clients they deal with and what is there turnaround on services.
It is not as horrible as you think. There are very few that might screw you over. But if you follow information provided above you will be fine. I like the fact that brought up a great question it is always good to be cautious in the beginning. If you need any help in looking for freelancers or where to look for them and how to manage them to be cost effective. Give me a call with any question you might have.