Other
The 101 Series: E Mail
This site from the 101 Series describes the difference between a POP3 email account and a Web-based e-mail account. It also has further links to setting up a web-based e-mail account, email ettiquette, email lingo and spam.
Other
The 101 Series: E Mail Lingo
This site from the 101 Series covers many of the abbreviations and acronyms that have been developed to save typing and emoticons to clarify the tone of the text.