I am an American and a professional writer so I do have a good grasp of English (although the British might disagree!). If you are working on the English version of the Handbook, look here for a tips on English grammar, etc. Please feel free to add to this discussion with your own tips. I plan on adding more later.
My Tip #1: Proper nouns are capitalized, common nouns are not unless they are a title. Therefor "Bessie" is capitalized; "cow" is not capitalized; and "Bessie the Cow" is capitalized. This is true for pronouns: "you" is never capitalized, nor his "he", "she", etc. unless they are the first word in a sentence. Sorry, my German friends! :)