This discusses different tips when writing an e-mail in order to gain the best results. Communicating with e-mail is quickly becoming a common form of communication in the workplace. A majority of my assignments through work come in the form of an e-mail.
Although basically the same tips are presented in the book, Ch. 12. Author Lyndsay Swinton adds a sense of humour to these tips. These tips also focus on what the e-mails says about you, the author.
This site includes other good info on business and communication skils. This article in particular mentions using EOM - End of Message - in your subject line if all the info you need to share is in the subject (see their example), then recipient then doesn't have to actually open the e-mail, making 1 point per e-mail (keeps them short, and you can send as many as you want - it's free) and make sure to respond! (simple courtesy).