Hiring translators online can be a much more complex (and dangerous) task then you might think. There are very good translators out there, but the industry is fraught with fraudsters trying to make a quick buck. They use a tool like Google Translate to try and pass off a translation as their own. You can see the temptation on their part - they can run your text through Google Translate or a similar tool, collecting hundreds (and possibly thousands) of dollars for just a few minutes of "work".
As mentioned, there are plenty of honorable and trustworthy translators out there who will produce stellar work. Here are some of the tips that I can suggest that have worked for me in the past.
1. To keep rates down, use rentacoder.com. If you use the online translation companies, you will normally end up being quoted an exorbitant amount per word. I know that I can't find just anybody to translate from English to Norwegian, but that doesn't mean that I am going to cough up 15 cents per word for a translation. If you look around, you'll find a much better solution. I like to use rentacoder.com. You will find plenty of people on there that can speak their native language (Norwegian, Swedish, whatever) as well as English. In many countries, learning English is required when going to school. I like to set a maximum price of 3-4 cents per word, and then multiply by the total number of words that need to be translated. That is the price that I will set as my maximum bid. I have never had a problem getting an order filled this way.
2. Use translators from countries that actually speak the language. After you place your order in rentacoder.com, you will start getting bids. I tend to only use people who reside in countries that actually speak the language that I want to have translated. If I need English to be translated into Norwegian, and one of the bidders is from Norway, then that is definitely a plus towards me eventually accepting their bid. I've had cases where people from India have tried to persuade me that they can actually speak Norwegian or Swedish. Maybe that's the case, but I'm take my chances with someone who actually lives in the country that speaks the language.
3. Use translators with high approval ratings. This applies to rentacoder.com. I like to use people with high approval ratings who have completed at least 5 jobs in the past. This is fairly standard stuff - just the same as purchasing from someone on Ebay who has a high approval rating.
4. Make sure that you mention in your bid that you only want human-translated text. Explain that you are going to have someone who speaks the language proof-read the translated text to make sure that it makes sense. This will help keep away some of the fraudsters.
5. If you happen to know somehow who understands the language, have them quickly go through the text to make sure that it makes sense. Obviously, is the text doesn't make sense, don't accept the work as complete.