Would you like to write a letter but you can’t think of how to start?
Right, click here and you’ll find a site with some useful tips to write both formal and informal letters. (info in Spanish)
As regards emails, this site from Hong Kong will teach you how to lay out an email properly. (info in English)
This other link from UK shows how to write different types of mails, such as business ones, emails to friends, and so on. (info in English)