If you don't have budget and it isn't for an external audience....G-sheets and G-docs have a couple of functions that work pretty well with translations. Beckie suggests DeepL as a handy translation platform that you could try (thanks Beckie!). I haven't used it yet but it looks very straightforward and you can translate word or powerpoint documents too!

In G-sheets, use the function '=GOOGLETRANSLATE'. This will translate a cell into the language you prefer – you just have to input the current language it is in and the ISO code for the language you want it to be. You can use the function '=DETECTLANGUAGE' to bring up the language ISO code of the cell. There are lots of tutorials online on how to do this :)

In G-docs, go to the 'Tools' menu and select 'Translate.' Then update your document title and pick the language you wish to translate it to. 

• Pros: Quick and free! 
• Cons: I wouldn't trust them 100% but if you have no budget and only need to translate some key words/short text it is worth a try! You can also double check by pasting the translated text into Google translate and seeing what it comes out with in English and catch any silly errors. 

If you have a limited budget ...and the document has an external audience, then you can find translators from all over the world on Upwork.com - a hub for freelancers. You just sign up for an account and you can either post a job advert or contact translators directly.

• Pros: Supporting the little guy and giving people from all over the world employment opportunities. 
• Cons: Sometimes the cheapest option is a false economy. I found less conscientious ones charge you just for copy pasting between Google translate! Depending on the type of material you are getting translated, you may need a specialist for the specific technical language and to proof read.

If you have a technical/important document or it is going to a high level recipient...hopefully you have a decent budget for this!

There are several approaches you can use - a lot of countries have a translators guild or an institution for translators that acts as a directory for reputable and specialist translators (usually pricey!). Embassies and government institutions have their preferred consultants but they are also very pricey! I usually ask for advice on good translators from stakeholders and partner organisations, as they have similar budgets and specialisms.

• Pros: Once you accept it costs a lot, you'll appreciate that it is well worth it. By using a good translator you'll end up with a well written document in the target language which increases both its credibility and usability.
• Cons: Budget! For large technical documents you are looking at thousands of pounds. You also have to allow a lot of time for this process.

General tips... Never skip on paying for proof reading! Ideally, get a 2nd proof read done by a technical specialist in that subject. Be mindful that even within one language, it can vary hugely depending on the focal country. I accidentally offended a stakeholder by using a Brazilian Portuguese translator for an Angolan Portuguese document. Take time to tailor things for your audience. :)