If you plan on writing an faq for Gamefaqs or the like, make sure to compose it in Notepad, and make sure you follow thier line restrictions. You don't want to compose a 100+ page walkthrough in WordPerfect only to realize it's 1000s of characters over the margine limit when it isn't word wrapped and it isn't the correct file type.

Type it as you play. Remember, try to use proper grammar and such, and if you aren't making a spoiler-free guide, remember to say that somewhere at the beginning of the faq. But if you were making an faq for someplace like EoFF, it'd be best to make a spoiler-free faq.