The ones I am familiar with are more established companies rather then fly by night shops that just setup a website one day and shut down the next. They also are mainly setup for professional studios that burn through many shoots a year, and are looking to outsource some of the "tedious" work we all know as photography :)
Shoot Dot Edit and Lavalu are the two big shops that I know people are using in the industry. They basically take all of the steps off your hands after you capture the images, to where you can send the proofs to the client. They will cull, color correct, enhance, crop, and process all of your images to what they call "dialed into your style".
I'm not sure if you can try these services as a one off image and a standard consumer. Honestly you could probably upload the image somewhere, and ask here in chat, and someone could edit it for you for free. But if you are more serious about outsourcing your editing work, try the above mentioned services.