There's not much need for me to write about the basics of email, because there's already plenty of good information out there on the Web. I've picked a few websites that looked good and here are the links:
PC-based: I highly recommend Thunderbird because it is very secure. It is also easy to back up the accounts, settings, address book and email for Thunderbird. But I mostly use Gmail. :-) [Mozilla sez]
Web-based email services, for example, Yahoo! Mail, Gmail and Windows Live (was Hotmail) are easier to use than email clients for many people. [comparison]
Mozilla.org tells you how to back up Thunderbird. About.com has backup and restore tips for Outlook Express, and you'll find other OE backup programs at TechSupportAlert.
Google, Yahoo! and Microsoft all back up your web-mail, but you may want to also have your own backup. One way is to simply save important messages to your hard drive. A better way is to use Mailstore.
Go to the safe email page to learn the other things you should know about email safety.
There are several things you can do to control spam. For example, use a "throwaway" address when you get a dubious request for your email address. The Spam page tells how to use throwaway addresses, as well as other ways to avoid spam.
*Never* reply to spam in order to be removed from mailing lists. All this does is let the spammer know that your address is real. The spammer will then sell your validated address to many other spammers and you'll be inundated by spam.
Here are some ways to maintain a permanent email address, even though you migrate with the seasons: