Netiquette / Etiquette ... it's all in your words!
Are there appropriate and 'not-so-appropriate' ways to communicate on the Web? 
Yes.  Netiquette" refers to "Etiquette", or proper way to conduct yourself, on the Internet. 

• Don't say anything you wouldn't say to a person's face or that you wouldn't mind having ANYONE read.  Just as when you write a letter, when you send written words through cyberspace --via email or on discussion groups  -- you have no control over where they go or who will see them.

• Remember you are talking to a person ... not a computer.  It's easy to forget that there is a person on the other end of the email or discussion group when you're sitting alone typing at your computer.  Be clear with your words.  It's easy for someone to misinterpret your meaning.  They can't see your expressions or hear the tone of your voice. Don't expect instant responses to  your emails or posts to a discussion group. 

• Use the Subject Line. Make your entry in the Subject Line concise and informative.

• Capitalize words only to highlight an important point or to distinguish a title or heading. Capitalizing whole words that are not titles is generally termed as SHOUTING!

• Never give your username or password to another person. 

• Never assume your email messages are private nor that they can be read by only yourself or the recipient.  Never send something that you would mind seeing on the evening news.

• Set your email program to NOT automatically copy the entire body of messages you are replying to when it's not necessary.  Take the time to edit any quotations down to the minimum necessary to provide context for your reply.  Nobody likes reading a long message in quotes for the third or fourth time, only to be followed by a one line response: "Yeah, me too."

• Focus on one subject per message and always include a pertinent subject title for the message, that way the user can locate the message quickly.

• Include your name at the bottom of Email messages.  

• *Asterisks* surrounding a word can be used to make a stronger point.

• Be professional and careful what you say about others.  Email is easily forwarded.

• Cite all quotes, references and sources and respect copyright and license agreements.

• Do not forward personal email to groups without the original author's permission.

• Be careful when using sarcasm and humor.  Without face to face communications your joke may be viewed as criticism.  When being, or trying to be,  humorous, use 'emoticons' to express emotion.  Emoticons are a series of keyboard characters that when viewed sideways, look like a face!  There are many emoticons that 'chatters' on the web use.  Here are a few:

  :-) :-( ;-)

  :-| :-p ;-p

  :-o 8-) 8-D

  :-D :-\ >:-)

• Acronyms can be used to abbreviate when possible, however messages that are filled with acronyms can be confusing and annoying to the reader.  Examples of some commonly used acronyms: