Even if your organisation does not have one. Here’s why.
By style guide I mean a guide to the use of language in communications, especially public communications such as websites and published reports. I don’t mean the brand guidelines used by graphic designers to make sure that logos and so on are used correctly.
Lots of organisations have a style guide. If yours does, you should use it.
If your organisation does not have one it is no excuse for poor quality, inconsistent writing. I recommend you find a style guide you like and adopt it.
You could, if you want, buy a style guide. The Chicago Manual of Style is the classic and expensive. The Economist Style Guide is available for under £10.
But there are free alternatives. News outlets are good sources. BBC News has its style guide is online and sets out ‘the rules of spelling, punctuation and grammar, as well as issues of accuracy, fairness and impartiality.’ The Guardian and the Daily Telegraph have online style guides, too. Try a search of [your favourite news outlet] + “style guide” to see if they have one.
Once you have chosen your style guide, bookmark it so that it is easy to find it when you need it.
What is really important is that you stick with one style guide. The whole point of this is consistency. It’s no good jumping between one style guide that requires acronyms to be upper-cased (e.g. NASA) and another that only capitalises the first letter (e.g. Nasa).