Read the privacy statement on a website, etc. before providing your email address to make sure you agree with it.
Don't publish/display your email address on web pages. If you must display it, use an alternate format. Example: instead of "firstname.lastname@example.org" use "jdoe at tcnj.edu." Make sure not to use a mailto: hyperlink since this would defeat the purpose of the alternate address format.
Be conscious of other places where your email address may appear such as discussion lists and newsgroups. Discussion list and newsgroup messages tend to be archived on websites and are good place for spammers to harvest email addresses.
Don't click on the "remove" or "unsubscribe" links on a suspicious email. Many times these simply verify that your email address is "alive" and valid.
Use email filters, either in your email client or servers-side filters. Our email anti-spam software tags emails that are suspected of being SPAM so that you can filter them more easily. It is best to discard SPAM messages or save them into another folder. Do not reject them since this will tell the spammer that your email address is still valid.