This guide is based on the style book which is given to all journalists at The Economist. The site contains various hints on how to use metaphors, punctuation, figures, hyphens etc. Brief and precise.
This site offers a wealth of information about hundreds of countries. The general categories include basic information, business information, and student information. Each country also has specifics: Greetings, Dress, Taboos, Law & Order, Videos, Gender Issues, Government, Major Religions, and many more
An older, yet very useful site that will help you to improve your writing on word & sentence level, paragraph level and also essay & research paper level.
iLoveLanguages is a catalog of language-related Internet resources Whether you're looking for online language lessons, translating dictionaries, native literature, translation services, software, language schools, or just a little information on a language you've heard about, iLoveLanguages probably has something to suit your needs.