I have created an English brochure for a client, and the same brochure was translated into German. Now I am being asked for a Korean version. Can someone provide some guidance on how best to proceed in Adobe Indesign CS5? I gather that I use Apple Gothic or another font... but it doesn't show up as Korean. Also, is Korean a vertically read font?
Korean is occasionally set vertically, but it's an extremely old-fashioned technique outside of a few limited areas - some ads, the spines of books, et cetera.
To be honest, I'd say "package your InDesign file and send it to a firm or freelancer that specializes in English to Korean translation, with experience in the subject matter of your brochure." It sounds like you are asking for automated machine translation within InDesign; ID has no such ability. There are ways to flow automated machine translations into ID documents, but you're most likely to find those tools in the hands of translation agencies anyways.
No matter where you get your translation done, I'd advise against you trying to typeset the Korean yourself - there are issues with Korean in English-language ID. Without some careful setup, ID will treat Korean characters as if they were Chinese, and will break Korean words in incorrect locations instead of at spaces.
A translation service has been hired to provide the proper Korean translation and they will have to proof the brochure.
What I am doing is initial legwork to ensure that I handle the translation correctly. I don't want to say something is possible and then get into the project and find out that it isn't.
Oh! I completely misread you; usually when I see "I use Apple Gothic or another font... but it doesn't show up as Korean" means "I changed the font but the language did not automagically become Korean."
Most of the issues I encounter come from the fact that translators typically deliver their work in Word format. If you intend to receive delivery in any other format, the following will be of little use to you. That being said: if your Korean text is marked as Korean in Word and has a Korean font applied (as it most likely will be supplied to you), then when you place your Word doc into ID you'll get a new "Korean" entry in the language-definition dropdown. If your text is marked in this way, then usually InDesign won't break the line endings incorrectly. It will be quite obvious when it's breaking lines incorrectly if you turn on hidden characters. If you make extensive use of paragraph styles - especially if you use Based On - then you should be careful whenever you import the Korean documents, as the translation of styles using East Asian features from Word to ID can occasionally behave in unpredictable ways, especially if the firm is using one of the many translation tools that sit on top of Word and use Word's styles for their operation.