What sort of a question is that? You just google translation, or translator or any other similar search term specifying what languages you want and hey presto! you have the choice of a zillion translation companies etc. Or you can use Google translate. It's so easy.
Okay, that's true. But let's say you are very particular about how your material is translated. After all, you have invested a lot of time and money to make sure it says exactly what you want it to say. You have been very particular about the tone and style used and you hope that your translation will convey this.
Your brand depends on it, or rather your new brand in the target language depends on it. This is part of another debate about translation vs localization and other concerns, which I may go into some other time. It is often not enough to simply translate. A good translator will guide you as to what makes sense for your target language reader or listener.
Choose a reputable translator (i.e. someone whose job is to translate, all day, every day, usually a freelancer, or independent) to do the work.
Talk to them (i.e. the translator - not a project manager, or sales guy) and find out how they work, and how they can be sure their work will do the job you need it to do.
It is of course evident that the translation should be good (that is another debate: what is good as regards translations?).
At the very least you should be happy with it. Before committing it to print or other forms of publication, run it past one of your trusted customers in the target language/territory. If they give the thumbs up, then you have probably found a good professional translator, who will listen to you, finding out what your true requirements are, and do their utmost to produce top quality material in the target language.
Does it matter where the translator is located? Some say that it matters little where your translator lives, or rests their head or hangs their hat.
In these digital times data can be exchanged in an instant; conversations can be had with people around the world (and you can even look them in the eye - in a manner of speaking - via webcam, smartphone or whatever other communication device you use).
Distance has, in some respects, been abolished.
Let us think about this, however. A native speaker of your target language living a few doors away from you can be met with very conveniently and they will, of course, have more knowledge of this language than you can ever dream of. They would seem to be prime candidates to do your translation.
This is the established wisdom. The ITI guide to buying in translations says that the native speaker on your doorstep will pride him or her self in keeping abreast of the latest developments in their native language. And this is true.
Again, the digital age is on your side. This native speaker can watch his or her favourite TV channels and listen to their favourite radio stations, read their preferred newspapers etc as if they have never ventured further than the local supermarket in their home town. They are surely totally up to date.
And indeed, compared to the translator of the analogue age who felt marooned in a foreign universe and heard only faint echoes of what was happening in their native tongue, they certainly are.
I would guard against exuberant optimism (to coin a phrase), though. Having been for many years myself in the position of the native in a strange land, I can vouch for the fact that despite all the ways you can imagine to keep up, you do get rusty. You sometimes have to search for your words. You may have to engage someone in the target language (your language) to have a look at what you have produced, just to make sure it flows correctly.
Thankfully I am now in England, so I am mostly immersed in an English-speaking universe, so I can mimic the tone and style you might be looking for to get your translation just right.
Do take care in selecting your translator. Have a look at where your native speaker translator is based. If they live in some far-flung corner surrounded by speakers of some obscure Martian language ask them how it has been since they had a chat with someone down the pub in their native language. It may have been a very long time. So it might be best to choose someone who is actually living in the target country.
Ask also, if they are based in a country were their mother tongue is spoken, how long they spent immersed in the language and culture of their target language. If they have spent only a year or two prior to gaining a 'translation qualification' they may simply not have a deep enough understanding of their target language and culture. They will be competent, but no more. They may miss the little thing that can make all the difference.
You, surely, are looking for more than mere 'competence'.
Do your homework, compare and contrast, speak to the people who will be doing the work. You will then have a good chance of getting a great translation, which may well turn out to be the cornerstone of your success.